This is fake news. The backing study for this claim did all sorts of wonky unrealistic testing to come to this conclusion. If you own an EV, you viscerally know it's BS given that you're the one paying for the actual tire replacements on your real-world driven vehicle.
To add to this, (from what I remember reading the study at the time) it was basically racing a car around a track (think lots of tyre squealing around corners), and found that the tyre wear was very high. I haven't seen a study which actually simulates somewhat "normal" driving (presumably because the wear is so low driving like that it's difficult to measure). Also didn't factor in a bunch of different stuff - tyres are effected by lots of things; compound, temperature, pressure, surface abrasion, etc. There might be an effect! But this study was very bad.
A normal driving test was (famously [1]) done to measure the effect of axle load (vehicle weight per axle) on road wear. This is where we got the “fourth power law” of road wear.
I think as a starting point, I would expect that tire wear should remain roughly in proportion to road wear, given the same tires on each vehicle. From this, I would expect car makers to use larger, thicker, heavier tires on heavier vehicles in order to compensate.
Thus I think we shouldn’t accept claims about the replacement lifecycle of tires without knowing these details of their construction. If an electric car is twice the mass of an older ICE car then the fourth power rule would predict a 16-fold increase in road wear. I would then expect the tires on the EV to have 16 times more rubber in order to last the same duration, unless they’re made of some newer compounds which are more durable.
> I think as a starting point, I would expect that tire wear should remain roughly in proportion to road wear
IMO this would be a suspect assumption to make w/o data to back it up. You've got two dissimilar materials interacting (in very different modes). E.g. rolling a metal ball bearing on a wood surface would obviously cause the wood to degrade far more than the ball bearing, (and even a wooden ball rolling on a wood surface would wear substantially less due to the mode difference).
(If I had to guess the road has a higher wear as the surface has a tensile stress around the contact patch of the tyre, causing most of the damage, but this is just armchair engineering at this stage).
The point I was after to make is that you can't assume that road wear scales the same way as tyre wear (I was assuming same material fwiw, just different loads). They are being worn under very different modes/scenarios.
Given that roads and tires experience the same forces under driving conditions (Newton’s Third Law guarantees this) I think it’s a reasonable prior assumption to start from. There are of course other environmental factors that accelerate road wear (rain and water erosion, freeze thaw expansion) but those conditions were not included in the study that produced the Fourth Power Law.
This assumes that road wear and tyre wear are caused by the same mechanism, but tyre wear is presumably caused predominantly by friction, whereas road wear is at least in part (and perhaps predominantly) caused by compression, creating pot holes by causing the earth underneath to move.
It's quite noticeable (to me at least) that the areas with highest wear are usually places that have heavy vehicles (buses and lorries) braking and accelerating. Traffic lights and bus stops will often have bumps/dips that seem to demonstrate a shearing force between the road surface layers.
I have always assumed it was just due to the uneven distribution of weight by vehicles often being stationary in the same spot, so those points are subject to more compression forces than the surrounding road surface.
If it were acceleration and deceleration I’d have expected the effect to be less localised, as breaking and accelerating happens over a much longer distance.
But, I have no actual idea. It’s just probably not friction…
I'm surprised there isn't more info available to compare vehicles/tyre wear. There's plenty of real-world driving going on, so you'd think someone would have measured tyre replacement frequencies.
Tires and driving styles vary a lot, so it would be really hard to come up with some aggregate numbers. Maybe you could compare the same very popular tire on different cars that still have enough data points to average out differing factors?
I reckon that the different driving styles could be partially dealt with by considering different classes of car. E
G. Fast "prestige" cars will tend to share certain driving styles and be quite different to cheaper run-arounds.
Ideally, it'd be great if insurance companies made a big push to get some kind of standardised "black box" that drivers could fit. As well as providing extra stats, I think they'd be great for detecting illnesses. A simple driving ability stat could be produced from the typical acceleration/braking timings - smoother is better as it shows good anticipation by the driver. If their stat starts decreasing more than expected due to aging etc. then the driver could be alerted that they should consult a doctor as it could cognitive decline, eye problems etc.
Maybe, but the average Tesla tire lasts half as long as my tires typically do, and the extra weight from the battery combined with the high onset torque are likely culprits (the former of which you can't fix with current battery technology when comparing otherwise apples-to-apples ICEs vs EVs if the EVs have non-negligible range, and the latter of which would require artificial limiting on the electric motor (which companies don't want to do because it's a selling point)).
For some rough numbers under normal/factory configurations to consider:
- A semi truck converts around 0.9 milliliters of tire to dust per kilometer.
- A Tesla Model Y clocks in at 0.3 ml/km
- A Honda Fit clocks in at 0.1 ml/km
Even with an overestimate of semis being responsible for 10% of total miles driven in the US, if everyone drove a Model Y then passenger cars would be responsible for 3x more tire dust than semis, and if everyone drove a Honda Fit then you'd be down to 1x.
Are there bigger concerns out there? Probably. Is the solution to bias toward ICE instead of EV? Probably not. It's not worth burying our heads in the sand when making those decisions though.
The weight difference between a Model 3 and the average new car sold in the US is a negative number. The Model 3 is slightly lighter than the average new car. So the difference comes entirely from torque.
The difference also comes from the grippier tires on the Model 3, the total tread volume on those tires compared to a smaller car, and that the Model 3 compared to the average car isn't apples to apples if you're looking at tire wear for ICE vs EV (to be fair, my car's too light to be apples to apples either, but if you look at comparably sized cars the Model 3 is heavier).
Electric cars don't have electric car-specific tires.
If you look at comparably sized cars the Model 3 is about the same. It's roughly the same size and weight as a BMW 3 series. And they're both around the size and weight of the average new car.
It's small electric cars that typically weigh more, because making the car smaller isn't the main way to make the battery smaller; reducing the range is. So then nobody really makes a small full electric car with a short range, because that market is served by plug-in hybrids that solve the range problem with a gas engine while still allowing you to do a few dozen miles a day as an electric car.
What specific tires do you have on those vehicles? Performance motorcycle tires wear much faster than non-performance (or your average car tire). Sportier car tires generally have softer compounds that wear faster. How you drive your vehicle also has an impact. Tire pressure.
You have a 4500+ lb car with 0-60 acceleration of 2.x to 4.x seconds and crazy torque, if you drive EVs like a teenager you will eat your tires after 10-12k miles.
There's nothing categorical about EVs that make them eat tires. The aggregate data about average EV tire life is skewed by the relative popularity of and poor choices made by Tesla.
EVs are heavier but it may not be that dramatic, M3: ~3500-3800lbs, Honda Civic: ~3000lbs
The torque is real, though, but I think this is what the earlier commenter was getting at regarding bad choices made by Tesla: there is no reason "chill mode" isn't the default, which makes a Tesla drive more like an ICE vehicle. Most other EVs I've driven don't go full torque by default, so seem to have made a better choice there.
In personal experience, I went about ~45k miles on 4 new tires in my Model S before I replaced them. A bit sooner than I would have in my Prius but not much.
I also don't take off from a green light as if I were in a drag race, which probably helps.
Torque and pedal response are just choices made in software. The weight is not as important, given the example of the Bolt EUV that weighs ~1700kg and has normal tire life.
> Torque and pedal response are just choices made in software
Yes which is due to the flexibility of EVs. The problem then is that customers are going to prefer buying vehicles with greater torque and manufacturers have little incentive to not provide EVs with high torque.
A lot of it is based on driver behaviour as it's quite feasible for ICE vehicles to be driven to burn rubber or make donuts.
If you include e-bikes and e-scooters as EVs, sure. If you mean cars and trucks, the F150 Lightning, the EV6, the Ioniq 5, the EX30, and every other vehicle is heavier than its ICE counterpart. The motors are inherently torquier too.
disclaimer: I drive an electric car but would sell it in a heartbeat if I could use transit or bikes to safely and efficiently get to work, the grocery, and the doctor.
It's Lenz's Law, friend. It's as much a design point as a=F/m. Because of it, induction motors and magnet synchronous motors generate more torque at 0RPM than any combustion engine I've heard of.
You could have software limiters, but you'd need regulatory mandates for that. Actually, I support that. 3+ ton trucks with a sub 4s 0-60 shouldn't be street legal. Or they should at least require a special license and liability insurance.
All EVs already use limiters because, as you correctly noted, just shorting the battery across the motor will rip the axles off and set the battery on fire. The question of whether an EV should put down grip-limited amounts of torque, or should limit itself to .5g at most, is a question of tuning.
So there’s not much in it. EVs do tend to be 10-15% heavier for the same model in EV vs ICE but the point is brought up constantly as if they are twice as heavy, or at least significantly heavier. In reality picking a model 3 would for your next car would bring the average weight of US new cars down which I think is interesting, no?
I mean... yes/no? EVs are on AS slicks, the tyre itself has less tread on it than something like CrossClimate 2. Overall they are replaced quicker and eat tread quicker. Its ~50% difference. I have both ICE and EV.
The new tyres that are coming out like Pirelli P Zero, promise a longer life span, but that remains to be seen.
