We've got 61,000 km on our Model Y. A small majority of the mileage is on the original tires, and the rest on our winter tires. Lots of tread left on both sets.
Want your tires to last? Don't drive like a moron.
I do know a couple of Tesla owners who had to replace their tires at 10,000 km. (7,000 miles). They learned their lesson and their second set is lasting a lot longer.
So much WTF in this article, like the regenerative braking thing as if the torque for both regular braking and regenerative braking doesn't have to be put through the tyres to slow things down.
I definitely buy people with EVs hooning it around the place wrecking their tyres. It is really easy and fun to make use of all that torque. But it's not actually required.
I also cannot see why regenerative braking alone is any different, in terms of tire wear, than caliper-on-rotor braking used for the same deceleration. There is something associated with regenerative breaking that I can see being a tire wear issue... one pedal driving.
In an ICE car, oscillating around the proper pedal position needed to maintain a particular speed leads to a cycle of coasting (not so hard on tires) and accelerating (harder on tires). With one pedal driving, at least with excessive oscillation, the cycle consists of regenerative breaking (harder on tires than coasting) and potentially more acceleration because the car slowed more rapidly. The more consistent you are at maintaining pedal position, the less the difference.
This might be best exhibited in downhill driving. An EV nudges the driver to be intentional about their downhill speed by applying regenerative braking, thereby requiring the driver to push the pedal down to reduce the braking. But on steep enough hills, there is still some braking. In an ICE vehicle, the driver might be more prone to just coast and let the car go a bit faster than they would have intentionally chosen.
I think you're absolutely right, assuming the driver is paying attention. Too many don't. I encounter a lot of people bouncing around in a 10-15 mph range (sometimes 20-30 mph) on the highway while they are looking at their phone. This happens in all kinds of vehicles, but the coasting vs. regenerative braking impact on tires emerges in these situations.
>He also speculated that “regenerative breaking,” where tires work really hard to stop due to torque stress instead of friction braking in gas-powered cars, as another possible wearing effect on tires.
A visual is a “twisting effect” of what happens with a dragster’s tires when a driver peels out, he said. Those tires have a shelf-life of roughly a mile-and-a-half when the soft, burning rubber vulcanizes and cracks.
I'm not sure I follow what you mean when you say regenerative braking doesn't have to be put through the tires. The only reason you can do regenerative braking is because the vehicle inertia wants to keep going forward, so you allow that rotation to be used to drive the rotor and generate electricity. The ground resisting that rotation is required for the motor to have a generative load put on it. Either way it's still more you are asking the tire to withstand.
He's saying that both regenerative braking and normal braking go through the tires. Both wear down tires via the same mechanism, so the call out in the article is BS.
By design, braking introduces drag onto the brake disc and in turn creates drag on the wheel. This drag is in opposition to forward momentum and so the rubber of the tyre flexes and gives to these forces a little at a time - resulting in slowing your forward momentum.
A rail car without rubber takes 10x-50x the distance to brake due to steel on steel friction.
Rubber is consumed from the tyre during acceleration, deceleration, and turning. Little rubber granules will roll off. The only time this isn’t happening is when the tyres aren’t in motion.
In motion the friction coefficient of rubber on asphalt (0.67) is not that far off from steel on steel (0.57) according to the internet [0]. That orders of magnitude difference in braking distance is more a result of train cars weighing 30-80t.
This comment does feel like talking to ChatGPT though, with the detailed clarifications the discussion didn't really require.
It doesn't change much, but note that unless you've blocked your wheels (and you have no ABS), you need to check the static coefficients. Wheels work so that from the point of view of the wheel the asphalt is still (i.e. there is no translation, only rotation).
This is why blocking the wheels increases braking distance: you suddenly have to deal with a much smaller friction coefficient.
> Wheels work so that from the point of view of the wheel the asphalt is still
In order to create a longitudinal force, the tire must have non-zero slippage. It’s not large (for typical mild driving), but it’s not zero if you’re using the tire to accelerate or decelerate the car.
Max acceleration forces are found around 10% slip ratio.
Well that and the fact that rubber melts and that changes some coefficients. Nothing about braking is as simple as one formula.
P.S. Isn't the static coefficient calculated for a stationary object trying to move against a surface? In a wheels locked scenario the wheel is sliding so the dynamic coefficient is the one to look at, accounting for the changed material properties of the heated/melted material.
Right, in the wheels locked scenario the dynamic coefficient is the one that matters, it's smaller than the static coefficient and that leads to a longer braking distance.
For a rolling wheel however, the stationary object is ideally just a point of the wheel, trying to move against the surface; but as soon as the wheel wins against the surface, the point rotates away and a new point tries to move against the surface. Even in the less ideal case a point of the tire always touches the same point of the asphalt from the moment it touches the ground to the moment it leaves it. So in that case you use the static coefficient.
Ouch, yeah - no GPT. I was saying that the rubber wear is a result of the above. Trains take a long time to stop because of their weight and lower friction on the rails. On trains it’s 0.35-0.5 not 0.57 [0]
Trains take a really long time to stop because the tracks frequently aren't clean - even a tiny bit of leaves or grease can cut the coefficient of dynamic friction down 10x
Of course you can but we're not talking about G-forces. That's a coefficient of friction [0], a dimensionless measure. It's determined empirically literally by rubbing things together and is then used to calculate the friction force between different materials.
It does but not because it influences friction at the wheel contact point (the mass cancels out in that formula). If braking is done entirely in "wheels locked" fashion then all that matters is the friction coefficient between the wheel and the track. But most braking is not like that. A train will only lock the wheels in emergency braking as that will apply larger braking force than otherwise available.
In normal braking the friction between the pads and the wheel is the important one and in that case the stopping distance is determined by how much of the energy of the moving vehicle you can bleed through the force you apply with the braking pads. More mass/speed, more energy, more time needed to apply the xxxxN of force to the wheel and convert the energy to heat. The energy of the moving vehicle scales with its weight while the maximum force a friction braking system can apply doesn't.
The science of braking is even more complicated than that, materials heat up or melt, friction coefficients change, tires behave differently under different loads, ABS systems kick in, etc. These are deceptively complicated topics.
The formula for friction also doesn't contain surface area and yet we use wide tires and big brake pads. But the bottom line is that in a real life scenario (as in not in simplified formulas on paper) the weight of the vehicle very much influences the braking distance.
When the wheel is just coasting (no additional torque supplied) you have the least amount of friction (assuming you’re going in a straight line) against the rubber. The issue with fly-by-wire systems is there’s no coasting. An ECU is constantly supplying PWM like torque pulses to the wheels to keep the speed constant. My OneWheel burns through rubber because of this. My EV as well. Yet my ICE vehicles or vehicles with a CVT/Open Diff that let the wheels run free don’t suffer from having to change the tires every few months. I believe that’s in corroboration with what the article is claiming. The soft compound tires for ride comfort get absolutely chewed. There’s ripple like wear from the motors.
One possibility - if you do regen braking as in one pedal driving, there is a lot less coasting to stop, and I imagine that is less stressful on the tires.
It's an interesting idea, but in general you don't come most of the way to a stop coasting in an ICE car unless you're already at a low speed. Usually you coast some, and then you have to brake significantly still.
It's Wyoming, the drivers who have EVs are probably burning up quite a bit of rubber with harsh accelerations and decelerations unlike the median driver elsewhere.
Only 800 people in the state even own an EV. As one of the select few EV owners you can easily accelerate past the vast majority of the other cars on the road in Wyoming.
There's about to be a few more as UPS and FedEx are getting EV's here in Wyoming soon. I am looking forward to hearing their experiences in EV delivery trucks.
I ride a 750 pound motorcycle. It has similar issues with chewing through tires unless you get a super long life, hard compound tire, which has its drawbacks on grip for cornering and braking. However I cannot lie to myself or anyone about how heavy it is. If it lays down, I have to pick up 750 pounds worth of bike.
No such option with EVs though. If your vehicle is nearly a ton heavier than a similarly sized ICE vehicles, you may never think about how that weight affects things and then comes the surprise that it affects all kinds of things.
EVs are cool. They are not a 1:1 replacement for ICE yet.
Hummer EV isn't really a representative EV though, is it? There are less than 3,000 EV Hummers on the road, compared to, for example, almost a million Tesla Model 3s. The Model 3 battery is about 1,000 lbs.
I had to convert that but yes, that is a very heavy bike. I have a 1200RT and yours is 100 kg heavier, goodness knows on what. I know that the Michelin Road 6 comes in GT versions with an extra ply for heavier bikes - maybe that's actually for yours and not mine!
Most people ride Michelin Commanders on these bikes (Kawasaki Voyager XII) but even the stock tires had sidewalls which cause low speed wobbles and unexpected handlebar locking right as you start to put your foot down. The front tire just doesn't have enough strength for the weight of the bike lol
That’s pretty nuts, I thought those were cruiser tyres specifically with softer sidewalls, whereas sports tourer tyres have those stiff sidewalls for better handling. I think all the K1600s I’ve seen, similar weight, had Metzler Roadtecs or Z8s on (great tyre BTW, always rated a Metzler front tyre, even if they wore out quicker than the Michelin, lovely while they last).
Still, sounds like an interesting characteristic to get used to. Always wanted a go on a really massive cruiser/tourer, but I struggled with my tutor/observer’s Pan European, made me realize that the RT’s design was a lot cleverer than I thought.
I wouldn't be surprised if they drive something like a Honda Goldwing - the undisputed Big Chungus of the motorcycle world, clocking in at up to 800 pounds [1].
You called it pretty close, it's a Goldwing competitor, the Kawasaki Voyager XII - 1200cc inline 4 cylinder. Half the engine that's in my Jeep Renegade lmao
Kawasaki Voyager XII, as someone commented to you it's a Goldwing sized touring bike with an inline 4 cylinder 1200cc engine. It shares a lot of blood with the Ninja so it's quite a fun bike even for its size, very maneuverable.
Tires last longer when you treat the controls as analog not digital. This is a problem for all terrible drivers, it turns out that a disproportionate number of assholes are also rich enough to buy electric.
Not just rich enough - the kind of person why has to have the latest and greatest. Very often insecure. You know exactly the sort of ICE car they would buy too.
Tyre damage is almost entirely caused by tyres slipping.
EV's could easily have a 'make tyres last longer' mode which prevented tyres slipping entirely by reducing power in all situations where the tyres are likely to slip.
The car has accelerometers in, and knows fairly precisely the downforce on every wheel, and has a reasonably good guess at the road surface, so should be able to make a pretty good guess at what point tyre slippage is likely to happen, and can then keep torque slightly below that the vast majority of the time.
As a bonus, if you can do this perfectly, you actually get more acceleration, since the coefficient of static friction is higher than the coefficient of dynamic friction for nearly all surfaces.
Well clearly not good enough if people are managing to wear out their tyres...
I suspect if you put a high speed camera on a tyre while someone was driving aggressively, you'd see many inches of sliding with every accelerate/brake.
Shouldn’t tire life be very similar assuming you accelerate and brake equally hard like in an ICE car? A Model 3 doesn’t weigh that much more than a Camry…
Want your tires to last? Don't drive like a moron.