> Moreover, modern traction control systems are just plain good. This isn't something exclusive to electric cars—even gas-powered vehicles have achieved decent torque vectoring by modulating brakes independently at each wheel, but modern EVs take it up a notch by performing thousands of software-based every second.
While this is not wrong it's also missing the fact that EVs use AC VFD motors that don't need to have a closed loop response under traction loss due to the fact that the AC field will slow down the wheel of it tries to over speed just by nature of how the mechanism works. This helps keep the wheels in the static friction region where traction is highest. In trains this and other factors[1] contribute to a 2x increase in traction over DC motors. With an ICE you have all sorts of momentum in the flywheel and drivetrain that are trying to runaway until the system/driver reacts and compensates.
Rear-wheel-drive vehicles have traction problems on slick roads. Losing traction on your front wheels is terrifying. I've had this happen before as I have had the opposite fishtailing with front-wheel-drive. Losing rear-wheel traction is something that can be compensated, but I don't think you can do much when you lose front-wheel traction.
No matter the powertrain layout if you lose traction on the front, ie understeer, you need to create a weight shift forward to restore traction.
I've done a couple rally instructional clinics, and one of the introductory drills they spent a fair bit of time on was just a giant circle of cones set up on dirt. You go around it faster and faster until the car breaks free into a slide, then you learn how to control and maintain that slide however you want. All 4 wheels have lost traction but you can still widen or tighten the radius by using weight shifts. Basically, you start steering using the pedals more than the wheel.
So you're not totally screwed if you lose front wheel traction, but this is stuff we don't teach in basic drivers ed classes.
In Norway, this is basic driver education. The drivers' license there requires "slippery road" training, which involves a more basic version of what you're describing.
In the land of the free, you can drive with a parent at 15 and get a license at 16 with zero required classes or real world driving test, with just your parent’s signature, a 70% pass rate on a written test and $25. That’s how I got my license in TX at least.
I think this is a bad thing, fwiw. The standards of driver safety training here are incredibly low.
It's like that in America because it has to be. If you required real driving skill from American drivers just to get a license, most of them would fail. It works in some other countries because people there are able to live without a car, and having a car is a luxury. In America, it's a requirement for basic survival in most places because America decided decades ago that it wanted things to be that way, and built everything with that basic assumption.
You can't expect good competency in something like driving from 99% of the public; you're just not going to get it, no matter what it is.
It varies by state, but most of them require either a driving exam or a piece of paper from a drivers education class. Texas is something of an exception in it's general lassie faire posture.
Funny enough, after moving back to Texas from out of the country in which my Texas drivers license expired by 6 months, I was required to take both a written AND a practical driving test. Keep in mind I was nearly 40 years old and had a valid Texas license since I was 16.
Same thing for anybody moving to US (or California at least). No matter what foreign country license you have, if you are moving to California permanently, (not tourist), you need to get a California Licence & foreign license will not give you any discount in process.
I was out of country for 9 years, and when I moved to California from China, they didn’t make me take the driving test since I had a California license before (7 years out date), but I was surprised.
Yes, once you get California Licence, the only time you would drive test again is if you upgrade, can't read charts, health issues, law enforcement reports.
When I moved to Alaska, in my early 40s, with a license in-hand from the state I had just moved from, they made me take a written test before issuing me an AK license. At least they didn't make me take a road test.
Got my license in California, instructor skipped the freeway part of the drive test which is mandatory.
Moved to Oregon, new licensees require both a written and a drive test but the DMV skipped them both because I already had an out-of-state (California) license.
Driver licenses are literally stupid easy to get here in the US.
I'm in Oregon as well and my understanding is if you have an existing valid license you can skip, but that's different if you've never had one or yours is expired. I had to do a driving test in my mid 20s because I lived car free downtown for a number of years and when my license expired just got an id card as replacement out of laziness.
You would be wrong, the handbook (and presumably the law it derives from) states (or at least stated when I took the test) freeway driving is a mandatory part of the driving test.
I asked the instructor why we skipped it, and they said it was because the freeway portion "is too dangerous for the instructors".
Easy to say one is wrong. I would not argue, but the fact is fact. For car, as long as your vision in 20/40 in each eye, & 20/70 in both, at least, no physical disabilities for car controls, no seizure or medical issues, no law enforcement referrals, you don't need to do freeway drive. Any Yes to any of the above things will warrant a Special Driving Performance Evaluation, and that most probably includes freeway 99% of the time (assuming there's a freeway access), plus some other things.
And for the record, no, no part of the driving test is dangerous for the examiner any more than for anybody sitting as a passenger. Routes are carefully designed to cover as much & as little as law requires, conditions allow, and much more.
Driving is pretty easy. I was operating heavy farm equipment at 11, and I’m not some sort of mechanical savant.
The maturity to make responsible choices is hard for younger kids. It’s probably smart to set limits to licenses to discourage bad behavior, but be real, some driver testing guy isn’t helping.
There is both a driver's training requirement, and a driving test required. The only "Texas" angle, is that parents are allowed to teach the driver's training portion (44 hours of total behind the wheel instruction). You can cheat that, but if you follow the guidelines it is pretty typical level of instruction for most states.
https://en.wikipedia.org/wiki/Driver%27s_licenses_in_the_Uni... says you can get a learner’s permit at 14 years old that doesn’t appear to have restrictions in Alaska, Arkansas, and one with restrictions (e.g. only daytime driving, limited # of passengers, only driving to school) in Iowa, Kansas, North Dakota, and South Dakota.
It seems there’s a strong correlation between population density and minimum age one can get a driver’s license.
In 2019 Norway had around 1/4 the fatality rate of the US. (In deaths/distance.)
But in 2000 it had a slightly higher rate than the US.
The road tests did not change, rather Norway changed how its roads are engineered (due to an initiative called Vision Zero!). So I doesn't seem like the more difficult testing actually helps much.
(BTW If you want to lookup numbers be aware most sites quote death/population instead which I find to be a misleading comparison.)
> So I doesn't seem like the more difficult testing actually helps much.
Brazil has a higher rate than the US, but you wouldn’t be able to tell based on the testing there. Mine was:
- Backup parking
- Parallel parking
- Drive around the city with an examiner for a few minutes
Any mistakes in the first two and you’re disqualified. You have to get them right the first time with no corrections (or at least that was the case back in 2007 or so).
For the driving part, you can make two small mistakes. Any critical mistakes immediately disqualify you.
In comparison, in my WA test when I moved here I botched parallel parking 3 times until I got it right. Then I indavertently speeded and also didn’t fully stop at a stop sign (either of which would’ve been a disqualifying mistake in Brazil IIRC). Still got my license.
Nevertheless, I find it MUCH safer to drive in the US (WA in particular, the only place where I’ve ever seen folks consistently driving at or below the speed limit). Brazilian drivers are crazy aggressive and in a lot of places traffic rules are treated as mere suggestions.
I only had one driving test when I was 15 in Mississippi. Drive around the court house block, no parallel parking. I moved to Washington the next year and only had to take the written test, and I’ve seen to be able to miss driver tests ever since even though my license has lapsed twice, the last time for 7 years.
I’m now back in Washington (Seattle), and I’m shocked at how often people run stop signs here.
And despite the easy testing I suspect you have not had any major traffic incidents.
That seems to be the way it goes in the US.
Running stop signs is not a sign of a bad driver, most stop signs in the US are not necessary (and really should be yield signs, except that's not legal to do that for no good reason).
Good old zero vision. It is being adopted all over the US now with tragic results for pedestrians and drivers. It's not in your head, the traffic lights are being changed to make you crazy. I both cycle and drive, and zero vision strikes an odd balance of making everything worse, except very specific urban environments such as Stockholm.
I've done a course like that but i question the value. The few hours i spent sliding around on a slippery track 10 years ago didn't really embedd the skills to the point that i would know what to do if my cars got in a slide today. Most people don't get into situations like that enough to train the skills regularly.
Living in a place where it snows has done a lot more for my skills. I would recommend to anyone that they find an empty, snowy parking lot and try throwing their car around a little just to see how it reacts.
That sounds really useful! I did something at a lower level, it was basically “defensive driving for teens” (I was 28 and twice the age of everyone else there, lol). It was run by a former racing car instructor in Phoenix and they had a FWD skid car that we practiced on. I was a pretty confident driver before the class but still found it very difficult to control coming out of the skid. I’ve been wanting to take a refresher to see if I’d handle it any better but haven’t found any classes near me, I should check for rally clinics
In FWD, you let off and it starts to steer. In RWD, once it's out of shape, you better know what you're doing to keep it in line.
Fwd is 10x easier for average drivers.
> I don't think you can do much when you lose front-wheel traction
Sure you can. A tire, any tire on any axle, will start to slide iff you're asking it to do too much work vs. the available traction. That's it. You can always do one (or both) of two things: ask the tire to do less, or increase the traction available to it. You have controls available to change both of these variables (steering and throttle).
Accelerating transfers weight to the rear wheels and lifting off the throttle (deceleration) transfers weight to the front wheels. The steering controls how much work you're asking the front wheels to do.
Once you grok this, it follows that RWD is easier and more controllable at the limit of traction due to separation of controls. The steering controls front traction and the throttle controls rear traction (but I'm simplifying, as the throttle also controls weight transfer thus traction on both axles). In FWD cars you have less fine-grained control since the throttle and steering are both using up traction of the front axle and the rear wheels are merely along for the ride. In a RWD car you can steer with the throttle without changing steering wheel angle.
All of this is car control 101. Which I wish was taught in the US as a prerequisite for getting a drivers license but sadly it is not, so approximately nobody has any experience in how to control a car when traction is less than optimal (rain, snow, oil on the street, etc.)
I urge everyone who drives to take a few car control courses to learn these basics. It can save your life, or the life of others, or maybe just some car repair bills. Totally worth it.
You can reason about the physics when reading about it online but there is no way to train your muscle memory to do the right thing other than by actually spending time practicing these skills in the real world, ideally with a car control instructor next to you.
yes, RWD can have traction issues, but modern (2006+) traction control handles this nicely. my RWD can be extremely squirrelly if I turn off traction control (I call it the "fun button"), but I've always felt I've had more control than what a FWD can offer me.
I've only driven older RWD vehicles so I experienced RWD + traction control. I just remember a couple freaky situations driving in older RWD on icy roads. FWD vehicles definitely had more control, but again that was in older vehicles.
FWD don't have more control under slippery conditions if your front tires break free.
RWD + traction control is pretty amazing. of course, it doesn't help too much in ice if you're running on summer sports tires, but that's an entirely different problem.
if you can, please use non-studded winter tires. they are much better to the roads, and typically have very good winter traction (just change them out for summer).
We live on a gravel road with lots of twists and corners. I taught all my kids to experiment on corners, go too fast, turn too hard, slide. Learn what it feels like, how to recover.
Eventually they could all do a 'controlled slide' around a corner and continue uninterrupted. They've all reported how useful this skill is later (they're all 25+) when they encounter slick conditions - they can feel what to do and respond quickly and intuitively.
I would think that front wheel drive would impair steering in tricky situations, while rear wheel drive would separate steering from drive and be better (with computerized help)
It's the opposite. If you lose back wheel traction in an FWD car, you "just" point your wheels in the right direction and accelerate - the front wheels will have both steering and power, so they will "drag" the car out of a slip.
With RWD you need more training for these situations, and it's more difficult to save a car.
With front wheels slipping it's also easier with FWD.
In either case, it's good to go for training lessons to learn how to deal with situations like these. Without practice your first instincts will most likely be wrong ;)
But the reason you lose rear-wheel traction on a rwd car is usually because of the motor. You are less likely to lose traction on the back tires with a FWD car.
The more things you overload (acceleration, brakes and steering) the harder it is for a tire to do the right thing.
One of the big negatives to sportiness in FWD cars has always been torque steer. But that is due to unequal-length driveshafts, not strictly the FWD-ness. A FWD EV shouldn't suffer from torque steer.
I do welcome RWD EVs, but let's not get carried away. Honda has demonstrated again and again that FWD vehicles are capable of very high track performance.
Very high performance != Fun. They are different. They say Miatas are fun to drive, and they are cheap, and therefore popular to race. But they are definitely not fast cars. I have never driven one, but I have always favored RWD cars, and never driven a FWD car that is anywhere near as fun. But that said, I haven't driven everything.
I came in a little hot trying to catch a yellow light on a left hand turn (US) and powerslid a Miata perfectly across 4 lanes... my second month of owning one and driving stick.
That's the day I fell in love with 50/50 weight distribution, rear wheel drive, and low and light weight.
You know what's not fun? Reading about a RWD car that slid into a roadside tree, killing the mother and child who had no training in drifting, like 99% of drivers.
RWD cars, even with modern ESP etc, should simply not be sold to untrained drivers.
They have been selling FWD cars for years with equal length shafts. It helps, but does not solve the problem. The newer, fancy suspension setups like the Civic Type R (mentioned in reply to you) get rid of most of the torque steer, but it's still there. If anything, all the extra bottom end torque from an electric motor is going to cause worse torque steer. The problem will not be solved by electric motors alone.
The torque steer in my FWD EV (BYD Atto) is horrendous. Sure its possible to use clever engineering to manage it, but just switching to EVs isn't going to magically make torque steer go away.
Is there a reason why EV's can't have a tiny second motor for redundancy and maybe a bit of traction? Dual motor EV's seem to be focused on performance and have two powerful motors.
I think this is just a side effect of most of the current EV offerings being expensive premium products.
Once cheap EVs become more common, FWD will return because having the motor in front allows for much more efficient energy recapture with regen braking.
How does FWD vs RWD matter for energy recapture in regen breaking? As long as you're not losing traction on your rear wheels during breaking, there's no difference in terms of energy captured in FWD vs RWD.
"As long as you're not losing traction on your rear wheels" is the key part.
The more you brake, the more weight shifts forward, which results in less traction available to use to recapture.
People vastly overestimate how much traction is available at the rear during braking, and running out of traction at the rear typically results in the car spinning (especially in an EV with low rotational inertia with most of the weight between the axles) so regen tends to be very conservatively tuned to not cause rear lock up, thus using even less of the little traction available.
Or used any vehicle with independent front/rear braking like a motorcycle or bike. The rear is for fine tuning while the front is for actually stopping.
They're both for stopping. It's why they're biased to have more power in the front than the rear. You can take advantage of this with the rear to "tune" in some situations, or to maintain stability at low speeds, but it should also be fully used when braking.
Also people who ride dirt bikes- the back will slide out fairly easily compared to the front (but using the front exclusively comes with some pretty big tradeoffs)
...or to anyone who ever rode a bicycle or motorbike with front and back brakes. Pull (bicycle) or press (motorbike) the back brake hard and the rear wheel tends to skid. Pull the front brake hard and the thing wants to somersault. The back brake is needed to stabilise the vehicle but the front brake does the real work.
Not on more modern cars. In an emergency stop situation the front brakes still do the work, but in normal more gradual stop situations traction control biases to the back wheels as much as possible so the front wheels can steer.
Rear-wheel energy recapture is surely fine so long as you are braking normally. Similar to driving a rear wheel drive car and just using engine braking.
Yes, when braking strongly rear wheels alone certainly don’t have enough traction: signs of strong front wheel braking are the nose of the car starts to dip and your passengers are complaining! Similar issue with slippery surfaces and no ABS (regenerative traction control)?
I would be interested to see some real-world figures of how often rear-wheel-only regenerative braking hits limits and wastes power.
In addition, are there limits to the amount of power regenerative braking can push into the batteries? I presume that even on front-wheel regenerative braking, when heavy braking occurs the front calliper is engaged and energy is lost. The theoretical difference between front and rear regeneration might not matter in practice?
Disclaimer: I don’t know much about this, and I suspect you are technically correct, but my guess is that it doesn’t matter in reality, and other constraints/costs/benefits matter more for deciding on front vs rear wheel drive.
Rear wheel regenerative braking (with a decent traction control system, which is table stakes) is fairly effective, but the down side is reduced life span of the rear wheels.
The front brakes do most of the work. It is not the case, as you assume, that both front and rear contribute equally to braking. If you didn't use the front brakes, or even if you tried to have them apply the same force, the rear wheels would absolutely skid.
If you want an extreme visual example, check out stunt cyclists who brake so hard the rear wheel comes off the ground. Pretty easy to see that the rear wheel isn't contributing to braking when it's in the air.
Bingo. When I was a kid, I once flipped my bike because I was only braking with the front. I learned not to do that, but to an extreme — I then braked almost always with just the back.
It wasn't until I got older and faster that I realized that braking just in the back is not as effective, since the braking action makes your nose dive and puts more weight over your front tire. I now brake with both sides, but always first in the back.
My commuter bike only has a front brake. You can shift body position to make it pretty much impossible to go OTB. Meanwhile my DJ bike only has a rear brake, which at best "strongly suggests" you slow down.
In cars that only have rear motors, unless you apply the brakes (or they have some blended braking setup) then ALL regen is via the rear motor.
Obviously, front brakes are capable of more braking, but the limit at the end of the day is the regen of the battery itself and how much the inverter can handle regen. RWD-only EVs are already capable of ~75kW of regen. Moving to FWD to try to gain regen is only marginally going to give you better efficiency, if anything. It only matters for harder braking.
Cheap EVs also aren't going to be filling the entire skateboard with batteries (or they won't be cheap), so the manufacturer can still achieve ideal weight distribution by positioning the battery cells further toward the rear.
I think the cheapest way of putting a car together will win.
I think front wheel drive cars were probably about economics instead of traction or braking. In fact front wheel drive always had weird transient effects on steering. I'm guessing economics of no driveshaft plus a transverse mounted engine.
But with EVs the drive motor is small and can fit anywhere, so that's where they will put it - anywhere.
It’s not such a straightforward equation any more. As the article explains, electric cars can play tricks with the weight distribution that ICE vehicles can’t, and I would put a modern rwd with the latest traction assistance features above a FWD car from the early 2000s.
Snow tires makes more of a difference than being FWD or RWD in heavy conditions is the real truth here.
> Snow tires makes more of a difference than being FWD or RWD in heavy conditions is the real truth here.
A FWD with snow tires or chains will almost certainly have better snow/ice handling than a RWD with snow tires or chains, by the simple virtue of the drive axle being steerable.
If you've played Kerbal Space Program or a similar spaceflight simulator + rocket designer, then the reasoning here should be pretty intuitive: if you can only apply thrust to the reverse, and don't have reaction wheels, then in space you have no ability to steer under your own control. You need to be able to point thrust to the sides if you want to be able to turn (or stop turning).
Same deal on an icy road. RWD means all your thrust is pointed backwards; FWD means you can point your thrust to the sides and control your car's orientation. Having both FWD and RWD (i.e. AWD or 4WD) is even better; sure, it constrains the overall thrust angles, but you also get more of it - which means better control when you're driving on a surface that ain't flat.
This ain't just theoretical; it's something I've repeatedly observed every winter here in the Reno/Tahoe area.
Not in my experience it doesn't. In icy or otherwise low-friction conditions, the steerable wheels being powered makes correcting for understeer and oversteer much easier than if they're unpowered - specifically because, per above, you can readily accelerate in directions other than forward/reverse, allowing you to orient the car even when sliding out. You can't rely on the tires' lateral friction to help you steer; a tire at an angle on ice will just slide with the rest of the car, and needs to be spinning to apply any force on said car other than forward.
The catch, though, is that you have to be willing to accelerate at the very moment your brain would otherwise panic and tell your feet to hit the brakes. Hitting the brakes will make things considerably worse by stopping the spin on your tires (especially the fronts, which are the very tires for which spinning is absolutely essential for steering control).
(In snow, this is a little bit less severe; the deeper the snow, the more pushback on the sides of the steering tires when at an angle, which helps a little bit with steering - but not nearly as much as on a dry road, thus still necessitating being able to accelerate with those tires)
> The actual virtue is the weight of the motor over the front wheels (coefficient of friction * basically weight above tires)
This also helps, but not nearly as much as the front wheels being able to accelerate in the direction they're pointed.
I have an 1/8 mile long driveway with a curve on a slope. I have sworn by an FF compact car with good snow tires (Used to be Hakka R's, but now Blizzak)
Snow tires are essential. I went out one day on Dec 31 without snows and made it about 300 feet from my driveway before I went in the ditch and rolled my car.
Circa 2008 I drove a FR Buick for a few weeks that had traction control and I was impressed with how it handled in the snow.
RWD are harder to drive on snow than AWD, that is a fact. Moving the weight helps on making them more similar to a front wheel drive (which traditionally were better than RWD on snow) but I don't think is even close to an AWD.
And snow tires is what makes a difference, true, but you can mount them on any car and same thing for traction control. So a same age AWD with snow tires drives better than a RWD with snow tires, specially if you come from a stop on an upwards icy road.
Snow tires don't hold a candle to the doubling(!) of contact patch over which torque is transmitted that you get going from FWD/RWD to AWD and no amount of low effort quips about steering and braking will change the fact that, among people who drive like adults, the ability to get up hills, cross snow banks where cross streets meet plowed main roads and get up to speed for a merge without anything dumb happening are the dominant factor in the "can I safely drive today" equation.
I've driven pretty much every combination of FWD, RWD, 4WD, and AWD, with and without snow tires, in a variety of winter conditions. The "other tires" were regular all seasons, not high performance summer tires or anything.
RWD with all seasons is really bad in snow, and mine generally didn't leave the parking lot in winter, because it simply couldn't. When you can start it, put it in reverse, let the clutch out, get out, and watch a wheel turning without the car having moved an inch, it's not a good day to take that car.
FWD with all seasons is better, because there's typically more weight over the drive wheels, but they're not great in snow.
4WD/AWD with all seasons (I lump them together because while there are some differences, it doesn't matter in typical snow) is far better, and hysterically fun to drive (drift all the wide corners), but it's still somewhat tricky in snow. And, yes, you do get better braking with 4WD, because the front brakes slow the rear wheels too (most of the braking force is on the front wheels, especially at initial application). The catch is that when you lock the wheels, you lock all four and have zero guidance, vs just locking the front and at least continuing mostly straight (or, usually, whatever the local downhill is).
FWD or RWD with snow tires is, by far, better than AWD with all seasons.
And then AWD/4WD with snow tires is just a case of "What snow?"
I have a FWD and AWD variant of the same car in my driveway and call bullshit.
Why is it so hard to believe that a product that advertises 30-50% improvement in traction results in a lesser improvement than doubling the area over which tractive force is applied?
I used to drink the snow tire kool-aid until I bought a set for the FWD car of and realized that better straight line stopping distance and cornering ability don't actually help you because being able to controllably put power to the ground is still the bottleneck in the "is it reasonable to drive in these conditions" equation by a mile and while they help they are nowhere near a replacement for doubling the contact patch that force goes through.
Sure, they get me a little bit of margin to be an idiot and come into turns too hot or stop short but I wasn't really doing that stuff in the snow anyway so the benefit is lost on me (and people adapt their driving style to the performance they have available so how big is the benefit really?) and they still don't make the FWD car climb my damn street like the AWD car does so I don't buy them anymore. I keep chains in the trunk for the really bad days.
The FWD/RWD nit picking is mostly irrelevant IMO because any fundamental difference is far less than the vehicle to vehicle difference within or outside a given category. Better handling in the dry more or less directly leads to better handling of the same type in the snow. A RWD box truck will out hill climb a FWD minivan but the latter will out corner the former and a Miata and hot FWD hatch will be better than both at everything.
You're not wrong in the sense that snow tires are designed first to stop you. Not to start you. But if you call snow tires on a FWD "kool-aid" I completely disagree with you there. unless maybe you bought "true" all seasons (tires where some of the tread is like a winter tire), which are still relatively new and have a lot of tread depth. Those can probably get you by OK to where you would think true snow tires aren't worth it. But once they wear I'd still take worn snow tires over them any day.
Source - Worked at a large tire wholesaler. Driven multiple FWD cars with true all seasons and true winters in winter conditions.
I've seen the true all seasons more and more. Both my and my mom's car have standard tires from the manufacturer, yet both also have the M+S designation that indicates a Mud and Snow tire. Are these tires of the form you describe?
It sounds to me like you already have picked this up but that M+S designation is kind of 'generously' applied in my opinion. At best it's relative. They will be better than a tire designed for dry pavement performance. But still range widely to how they perform compared to actual mud or snow tires.
I've lived it (these were proper studded snow tires). The improvement is there any very tangible but there's a reason I put the wife in the AWD one.
I agree that tread depth is massively important in the slushy conditions that commutes in the snow devolve into. You need that depth to provide a path for the "thick water" to GTFO so you're not hydroplaning on slush.
Does your AWD car with summer tires brake better in icy conditions than your FWD?
> better straight line stopping distance and cornering ability don't actually help you because being able to controllably put power to the ground is still the bottleneck in the "is it reasonable to drive in these conditions" equation
I take this to mean the answer is no. I drive in serious winter conditions, and AWD with winter tires is great, but it doesn't matter how many wheels are applying traction when you slide into a ditch.
Of course something on harder tires will not brake and turn as well as something on softer tires.
The reduced ability to stop and turn has lead to in my snow driving experience, far, far fewer "that could have easily gone worse" situations than a lack of ability to gracefully put power to the ground.
I don't get why everyone obsesses over stopping and turning and shills snow tires. There's a reason that everyone and their brother buys an AWD vehicle and far fewer people buy snow tires. Everyone(TM) can't be wrong.
What I want you to tell me is why I should prioritize braking and steering if they're not the bottlenecks I encounter when driving in the snow.
> I don't get why everyone obsesses over stopping and turning and shills snow tires.
Most accidents are caused by failure to stop and failure to turn, not failure to accelerate.
> There's a reason that everyone and their brother buys an AWD vehicle and far fewer people buy snow tires.
You clearly live in a very different place than me - very few passenger vehicles are available with AWD (subarus, trucks, some SUVs). But everyone has snow tires.
> What I want you to tell me is why I should prioritize braking and steering if they're not the bottlenecks I encounter when driving in the snow
Great for you? Again, you clearly live in a place with very different conditions than I do. What about the conditions make it so that you can't accelerate, but you can turn or brake just fine?
I live in Minnesota and very few people buy snow tires, and most balk at it. They don't realize the difference it makes.
I regularly drive in conditions in my damned Camaro where the only other vehicles on the road are trucks, with some of them not being on the road anymore.
Interestingly, I'm finding more and more standard vehicles with tires with the M+S designation on the sidewall that makes them legally Snow Tires. I don't expect these have the same performance in the midwest snow as purpose-built snow tires, but they should qualify from a legal sense for chain restrictions and the like.
As somebody who learned to drive in snow in a RWD vehicle, I think FWD is frankly ridiculous in slippery conditions. If you lose traction in the front, you lose all control of the vehicle. With RWD, you rarely lose traction on all 4 tires, so you always have at least one working control. I've never really gotten the hang of driving FWD in snow, and greatly prefer RWD.
The trick, in my experience, is to learn how to get into a tailspin and do donuts. Unplowed parking lots are best for this. When you're familiar enough with the vehicle to do controlled tricks, you're just about prepared for an emergency. I've never owned a FWD car through a snowy winter; it's really down to what you're experienced with.
It's easy. You point the front wheels in the direction you want to go, and accelerate. The front wheels will dig the snow and also throw it off the wheels if you spin them really hard so clean tires can bite better on the snow.
I know this on an intellectual level; like reading a book about riding a bike. But my learned instinct is to use my accelerator to control the rate of spin, which is a horrible mistake in FWD.
> If you lose traction in the front, you lose all control of the vehicle. With RWD, you rarely lose traction on all 4 tires, so you always have at least one working control.
You've still got one control working in the rear: brakes. The understeer characteristics of a FWD car are very easy and intuitive to recover from. If someone can't manage traction in an FWD understeer condition, they almost certainly lack the skills to manage oversteer.
> The understeer characteristics of a FWD car are very easy and intuitive to recover
This might be true when discussing snap over-steer and throttle induced under-steer on a track but is a complete lie for snow driving where most drivers will just keep steering harder in response to under-steer which is not productive and you don't have enough traction for lifting and braking to induce much extra weight on the front.
> most drivers will just keep steering harder in response to under-steer
That's my point. Make the wrong correction in RWD car and you end up oversteering beyond 90 degrees in an unrecoverable spin. The failure modes of FWD understeer in the snow are all recoverable.
Also losing control and hitting a tree with your front crumple zone is much better than hitting the same tree side on with the driver door
That is the understated safety factor of understeer, but people prefer to think in terms of never doing mistakes instead that in terms of overall safety
>That's my point. Make the wrong correction in RWD car and you end up oversteering beyond 90 degrees in an unrecoverable spin. The failure modes of FWD understeer in the snow are all recoverable.
You're making one of those textbook correct but reality wrong statements that clipboard warriors love.
Sure, you can recover from under-steer but if you're already doing the wrong thing and pointing the wheel where you want the car to go you almost certainly won't.
With over-steer if you do the "natural" thing and steer the wheels toward where you want the car to point at least you have a chance. Sure many people might flub it but that's a heck of a lot better than the "no chance" you get if you react the same way to under-steer. Also, if you do over-correct the over-correction may very well not be as severe as the initial over-steer giving you a better chance to get it right the second time.
Sure, under-steer is theoretically recoverable and with over-steer you can theoretically spin or slide backwards but in reality in "on the street" situations (i.e. not what you see someone doing on an old taxiway in a training video) 99.9% of the time you'll have hit something long before either happens.
Edit: Since I'm apparently so wrong anyone care to explain? Or is it just "sideways bad because smart man with vest and clipboard say so".
> If you lose traction in the front, you lose all control of the vehicle
You only have so much traction to accelerate, brake, and steer. Sharing them on the same wheels seems objectively worse at the limits to me, except in the sense that every car is all wheel stop.
I think some of the safety issues associated to RWD were problems of the days where they were more common. Trucks need weight in the back, we know that, and winter tires are way better now.
You have to learn how the car handles when it's not an emergency to know what to do in a panic. I toss every car I own around in a snowy parking lot at least once so I know what it'll do. This seems insane to a lot of people I've talked to.
That said, I think understeer is safer and more predictable in most situations for people who use their cars as a transportation appliance. You point and shoot, so to speak. Most people aren't driving at the limits.
Strictly speaking, if your car is out of control, you're driving past the limits. The whole point of the parking lot exercise is to learn where the limit is. I drive like a granny, but prepare for the worst. And I've learned over the years to avoid the first day of snow in a season.
I've driven a Camaro year 'round in Minnesota for the last 10 years. The only place I've gotten stuck is our own (sloped) driveway, a few times. Snow tires are amazing, and it's ridiculous how few people have them here. It's always a hoot borrowing someone's pickup in the winter that they feel is oh-so-good in the snow and realizing how carefully I need to drive it because of their all-season tires. I literally plowed a road with the front of my car this year through nearly 2 feet of snow.
To be fair, they probably wouldn't get stuck in my driveway but I can stop a hell of a lot quicker and turn if necessary. I also find controlling a near spinout to be more intuitive on a RWD vehicle than a FWD one, but that might be just because my first car was RWD as well.
RWD cars allow you develop a much higher degree of skill at driving because of the requirement to separately manage traction on the drive and steering axles.
For one thing, you can enter and maintain a drift in an FR car. In a FF car you can easily enter a drift but the car will either straighten out or go into a spin.
I’d tell you about my tactics for going around corners fast in a FF car but I’d get downvoted…
There are also (rare nowadays and are mostly available in higher end / performance cars but used to be more frequent in late 80's and 90's):
FF 4WS
FR 4WS
4WS is for «four wheel steering» (the emphasis is on «steering», not «driving») where – depending on the travelling speed – the rear pair of wheels turns either in the direction opposite to the front wheels (≤ 20 kmh) or in the same direction (≥ 20 kmh). The former makes the parking easier and reduces a turnaround circle. The latter makes the car look moving sideways when going around a bend or disappearing from its lane and emerging in the neighbouring lane during the lane change. 4WS also handles a bit differently on slippery roads around the bends.
You can maintain a drift in an FF car. The overall concept of weight shift is the same. You can even selectively lock up the rears without using the hand brake by using throttle to overpower the brakes on the front but not the rear.
Source: was taught this stuff by someone that won SCCA autocross nationals, as well as a few podiums in rally. Go to any rally event and you'll see plenty of FF cars doing every drift you can imagine through corners.
Back in the days this could also be used for performance reasons, to keep the turbo on, preventing it from needing to kick in again upon re-acceleration out of of the corner (back then turbo lag was huge and the "kick" was hard to control).
This technique was known to be very harsh on the engine but some races pilots would do it anyway.
Was only a matter of time IMO. The two big enough to matter pros to FWD are packaging (no pesky drive-train competing for space) and stupid proofing (in the form or more forward crashing and less sideways crashing). EVs solve the former. Modern computer control solves the latter, though side curtain airbags, pre tensioners and modern expectations of seat bolstering had long since diminished it.
Trying to make two tires do all the going and the lion's share of the turning is just silly for a variety of reasons (competing design goals for suspension/handling, tire wear, performance, etc) and without some big pros to make up for it there's no reason to incur that.
Of course some applications that have cargo space as the utmost priority will remain FWD forever (Promaster style vans, probably some station wagons and subcompact hatches, etc) but for more rounded cars, especially ones with AWD optional having RWD be the default just makes too much sense from a suspension design and handling perspective to ignore.
I live in a rural mountainous area. FWD cars have a huge advantage over anything RWD: traction going up hill. Nothings funnier than watching delivery trucks going up a giant hill backwards because it's the only way they can maintain traction.
I see what you mean: an engine leans a truck forward, particularly because the truck's engine is usually farther in front of the wheels than it would be in a car.
I imagine that's exasperated by the fact that everything behind the cabin is built to be as minimal and lightweight as possible, but the overall design is made to support a heavy maximum load filling the bed. Without significant weight in the bed, the truck will naturally lean forward.
Unfortunately this all applies to trucks, and does nothing to help my FWD Civic accelerate up a snowy hill.
Your civic still has more weight on the front wheels than the rear, unless you overload it. (I've never looked at the specs on a civic, but most cars are not rated for much weight.)
Yes, but that weight isn't in front of the front wheels. The center of gravity rests between the front axel and the driver.
When I accelerate, the center of gravity moves back to the middle of the car. Accelerating up a hill puts that center of gravity in the backseat near the rear axel.
This is not my experience. I have a house in the mountains with a steep-ish driveway and the only way to make it up the driveway when it snows 4-6" is by going backwards. I frequently have to reverse up my driveway in order to get enough traction. The weight shift just kills FWD traction. I'm sure RWD could have other issues, proper AWD is clearly the way to go.
Having switched from RWD to FWD (Mercedes-Benz to Volvo), I'm not sure about this. Climbing up hills in the winter definitely felt worse in FWD, since all of the weight is going into the back and even with studded tyres, it felt like my front tyres were constantly slipping.
If I got to choose my drivetrain, I'd go AWD > RWD > FWD.
> FWD cars have a huge advantage over anything RWD: traction going up hill.
You got that backwards.
Forward acceleration transfers weight to the rear axle. The harder you accelerate, the more weight transfers to the rear, which means the more traction is available to the rear wheels, less to the front wheels.
It's easy to visualize if you think of the case of extreme acceleration such as in a motorcycle or drag race car - the front wheel(s) lift off the ground entirely and thus have zero traction.
Going uphill only accentuates this even more, so FWD is going to be at an even greater disadvantage.
While this is not wrong it's also missing the fact that EVs use AC VFD motors that don't need to have a closed loop response under traction loss due to the fact that the AC field will slow down the wheel of it tries to over speed just by nature of how the mechanism works. This helps keep the wheels in the static friction region where traction is highest. In trains this and other factors[1] contribute to a 2x increase in traction over DC motors. With an ICE you have all sorts of momentum in the flywheel and drivetrain that are trying to runaway until the system/driver reacts and compensates.
[1] http://www.republiclocomotive.com/ac-traction-vs-dc-traction...