Tires Designed for EVs

[Big Dog]

I agree, pretty much a marketing gimmick.

Not sure that is fair. These tires do contain a couple of treads of hard rubber for better range, so they do have some different engineering behind them. That said, any tires that are rated for the car load will be great. Whether the extra % range is worth it depends on your situation.

Personally, in SoCal, I'm all in on summer tires for handing (but summers take a range hit), so a few threads of hard rubber for a range boost is worth trying (to me). I plan to replace my Contis with Michelin EV.

 

[ATPMSD]

Not sure that is fair.

To be fair I went back to try to validate my opinion and did additional reading. Here is what I found:

Questionable

• EV tires as built for heavier cars - all tires have a weight rating. It seems to me as long as we use an appropriately rated tire this is not a “benefit“
• EV tires are harder and last longer - all tires have a treadware rating, so if the rating is the same for a standard tire versus an EV tire I see no “benefit”

Pros

• EV tires offer better traction to better support acceleration and regen braking. As I understand it, EV tires have a lower number of groves which puts more rubber on the road but does not scarfice wet road breaking as the extra weight of the car aids in water removal. This is pretty cool.
• EV tires have stiffer sidewalls which enhances turning performance
• EV tires are quieter
• EV tires have a lower rolling resistance. I can see how this might work and it would increase range.

Fair enough?

 

[Darwood77]

Thanks. I am leaning toward those Nokian One all-seasons for our next set on our Model 3 LR. I would love to hear a longer-term report, if you care to, after a few months.

I do plan on updating my thread periodically.

 

[KenC]

I know we all are trying to figure out what is the best tire for our specific use. Being in Maine, I had to choose between two pairs of tires, a Summer and a Winter; or one of the new Snow tires that can run all year round, the 3PeakMountainSnowflake tire.

When I made my decision back in 2019, there weren't any rims that I liked for dedicated snow tires, soI decided to try the new 3PMSF tires. There weren't any EV-specific tires to consider. I considered the Vredestein Quatrac5, and the Michelin CrossClimate, but the Michelins were out of stock so I got the Vredesteins.

I've been very happy with the Vredesteins. I don't care as much about longevity, as I only expect 2-3 seasons on snows, if I want max grip. I've driven about 26k on my Quatrac5 and 3 winters. When Fall comes, I'll have driven over 30k, and I'll replace them. Probably with the Michelin CC2, but maybe the Quatrac Pro.

Compared to the OEM tires, the Quatrac's have very similar noise, comfort and efficiency. The big difference is snow grip is a lot better. The efficiency surprised me, as I assume snow tires will just get worse mileage, but my efficiency has been approx the same with the OEM tires and the Quatracs. I'm averaging about 250Wh/mile. ABRP measures my efficiency at 65mph at about 235Wh/mile. That's impressive, as far as I can tell. Very good tire.

 

[gearchruncher]

• EV tires offer better traction to better support acceleration and regen braking. As I understand it, EV tires have a lower number of groves which puts more rubber on the road but does not scarfice wet road breaking as the extra weight of the car aids in water removal. This is pretty cool.
• EV tires have stiffer sidewalls which enhances turning performance
• EV tires are quieter
• EV tires have a lower rolling resistance. I can see how this might work and it would increase range.

You just described the holy grail of tires. More grip, less rolling resistance, better turning, same wear?

And instead of selling these as performance tires, they sell them as EV tires, even though they would be better for every single car ever made?

EV tires are harder and last longer - all tires have a treadware rating, so if the rating is the same for a standard tire versus an EV tire I see no “benefit”

FYI, there is no standard rating for treadwear. Different manufacturers do it differently. A 500TW tire from Michelin is not the same as 500 from Bridgestone.

 

[ATPMSD]

FYI, there is no standard rating for treadwear. Different manufacturers do it differently. A 500TW tire from Michelin is not the same as 500 from Bridgestone.

Good point!

"Treadwear grade: A government-required number that indicates a tire’s expected wear. A grade of 300 denotes a tire that will wear three times as well as a tire graded 100. But the numbers are assigned by tire manufacturers, not an independent third party."

The Truth About Tire Treadwear

The only way to truly predict how long a tire will last is to test it. That is exactly what Consumer Reports does with an extensive on-the-road program tire treadwear test. Here's how we predict tread life.

www.consumerreports.org

 

[ATPMSD]

You just described the holy grail of tires. More grip, less rolling resistance, better turning, same wear?

And instead of selling these as performance tires, they sell them as EV tires, even though they would be better for every single car ever made?

This is my guess:

Most people do not buy "performance" tires and true performance tires have stiff sidewalls and are a lot more grippy, which means they wear faster. With EVs there is now a market to sell these more expensive "EV tires" as "standard" tires, which is why I think we may now be seeing them. No idea if this is true, just speculation.

 

[jackmott]

Not sure that is fair. These tires do contain a couple of treads of hard rubber for better range, so they do have some different engineering behind them. That said, any tires that are rated for the car load will be great. Whether the extra % range is worth it depends on your situation.

Personally, in SoCal, I'm all in on summer tires for handing (but summers take a range hit), so a few threads of hard rubber for a range boost is worth trying (to me). I plan to replace my Contis with Michelin EV.

Tires designed to improve efficiency existed before EVs were a thing, and it isn't done with hard rubber, quite the opposite, you want the tire as supple as possible so that deformation doesn't waste energy. The soft sticky tread of performance tires isn't necessarily bad for range, what tends to hurt it is the efforts to limit lateral deflection in the sidewall, which adds material and makes vertical deflection more energy wasteful as a side effect.

 

[3sr+buyer]

I've been very happy with the Vredesteins. I don't care as much about longevity, as I only expect 2-3 seasons on snows, if I want max grip. I've driven about 26k on my Quatrac5 and 3 winters. When Fall comes, I'll have driven over 30k, and I'll replace them. Probably with the Michelin CC2, but maybe the Quatrac Pro.

Compared to the OEM tires, the Quatrac's have very similar noise, comfort and efficiency. The big difference is snow grip is a lot better. The efficiency surprised me, as I assume snow tires will just get worse mileage, but my efficiency has been approx the same with the OEM tires and the Quatracs. I'm averaging about 250Wh/mile. ABRP measures my efficiency at 65mph at about 235Wh/mile. That's impressive, as far as I can tell. Very good tire.

The (now discontinued) Quatrac 5 has been mentioned in some reviews as being one of the lowest rolling resistance tires. Unfortunately, the Quatrac Pro and CrossClimate2 do not have this reputation, so do not be surprised if your efficiency gets worse if you replace with one of those tires.

 

[gearchruncher]

and it isn't done with hard rubber, quite the opposite, you want the tire as supple as possible so that deformation doesn't waste energy.

Pretty sure physics doesn't work that way. Harder rubber balls bounce higher (more energy recovery) and trains use steel wheels. We build a newton's cradle out of the hardest materials we can find. Any deflection is energy loss, that's just how materials work. You're also arguing that running lower tire pressures would reduce rolling resistance, and that soft, bendy tires would warm up less than very stiff tires when driven. Just because a material is elastic (like rubber) doesn't mean it doesn't absorb less energy than if it didn't deflect at all.

 

[3sr+buyer]

Tires designed to improve efficiency existed before EVs were a thing, and it isn't done with hard rubber, quite the opposite, you want the tire as supple as possible so that deformation doesn't waste energy.

Lowering the air pressure would make the tire more supple. But that generally worsens efficiency because the tire deforms more and loses more energy as heat.

So an efficiency-at-all-costs tire would likely have a hard tread compound, stiff sidewalls, and high air pressure capability to reduce how much is squishes.

 

[jackmott]

Pretty sure physics doesn't work that way. Harder rubber balls bounce higher (more energy recovery) and trains use steel wheels. We build a newton's cradle out of the hardest materials we can find. Any deflection is energy loss, that's just how materials work. You're also arguing that running lower tire pressures would reduce rolling resistance, and that soft, bendy tires would warm up less than very stiff tires when driven. Just because a material is elastic (like rubber) doesn't mean it doesn't absorb less energy than if it didn't deflect at all.

As you lower tire pressure you deform the tire casing more, and thus lose more energy. This is why raising tire pressure a bit tends to improve rolling resistance, there is less deformation of the tire, so less losses due to hysteresis. If you make the pressure too high, you will lose energy to impedance. There is a great writeup on this topic in the context of bicycle tires here: Part 4B: Rolling Resistance and Impedance

If you had a perfectly smooth road and didn't need to make turns a solid metal wheel would be great, no hysteresis at all. But we need the tire to deform, and we need it to do so with as little hysteresis loss as possible. Hence we used pneumatic tires.

 

[jackmott]

Lowering the air pressure would make the tire more supple. But that generally worsens efficiency because the tire deforms more and loses more energy as heat.

So an efficiency-at-all-costs tire would likely have a hard tread compound, stiff sidewalls, and high air pressure capability to reduce how much is squishes.

If you need a sanity check here, go look at a Michelin MXM4 vs say a Pilot Sport 4S, and compare the sidewalls and how readily they deform in your hands. You will find that reality is not matching your current mental model of the situation.

 

[gearchruncher]

If you make the pressure too high, you will lose energy to impedance.

Yes, but the idea that a 4000 lb car with a 240mm wide tire and a full suspension treats a tire anything like a bike with no suspension and a 3mm contact patch is false. You have no idea where a car tire is on this supposed "hysteresis vs impedance" curve.

It's well proven in car tires that rolling resistance is highly tied to grip. There are tons of elements to this, all the way down to how the tread deforms into the non-flat pavement. You're seriously claiming that if they just threw a super soft sidewall on a Hoosier it would have less rolling resistance than a 500TW all season?

 

[3sr+buyer]

If you need a sanity check here, go look at a Michelin MXM4 vs say a Pilot Sport 4S, and compare the sidewalls and how readily they deform in your hands. You will find that reality is not matching your current mental model of the situation.

The Primacy MXM4 makes some compromises for ride comfort, while sportier tires like the Pilot Sport 4S need to make fewer compromises for ride comfort.

 

[jackmott]

Yes, but the idea that a 4000 lb car with a 240mm wide tire and a full suspension treats a tire anything like a bike with no suspension and a 3mm contact patch is false. You have no idea where a car tire is on this supposed "hysteresis vs impedance" curve.

It's well proven in car tires that rolling resistance is highly tied to grip. There are tons of elements to this, all the way down to how the tread deforms into the non-flat pavement. You're seriously claiming that if they just threw a super soft sidewall on a Hoosier it would have less rolling resistance than a 500TW all season?

The physics behind a pneumatic tire on a bike and on a car is absolutely the same. And yes, performance tires usually go to great lengths to reduce lateral deflection in the sidewall, which adds material there and increases hysteresis losses while rolling. It is not directly tired to the compound being softer. There are tires out there that manage to have good grip and good efficiency, for instance the Pilot Sport 4 non-S.

 

[jackmott]

The Primacy MXM4 makes some compromises for ride comfort, while sportier tires like the Pilot Sport 4S need to make fewer compromises for ride comfort.

Better comfort also improves rolling resistance. The ideal pneumatic tire would have *only* the gas inside being compressed as the tire rolls and no solid materials at all. Sadly we need a little bit to hold the air in there, and to stick to the road.

 

[gearchruncher]

The physics behind a pneumatic tire on a bike and on a car is absolutely the same.

Really? What lateral loads does a bike tire need to support? If you're laterally loading a bike tire, you're falling off. And where is all the structure in a bike tire designed to support a huge flat contact patch?

But independent of that, you're saying it's a curve between hysteresis and "impedance". There's zero evidence that even if a bike tire is in the trough of that curve at ~60 PSI that a car tire would be anywhere near that trough at usable pressures or compounds.

 

[gearchruncher]

The ideal pneumatic tire would have *only* the gas inside being compressed as the tire rolls and no solid materials at all. Sadly we need a little bit to hold the air in there, and to stick to the road.

Yeah, but if "Sticking to the road" wasn't part of the equation, we'd use steel tires with no air at all. We'd still prefer ZERO compression over just gas compression. By definition, compressing the gas obeys PV=nRT, which means temperature increases, which means we will lose some of that energy to the universe. No proof here that the gas compression loss is less than occurs in rubber.

So actually a very hard and stiff pneumatic structure makes this closer to a steel wheel, which is known to basically be the lowest rolling resistance thing we can reasonably make, yet you are continually claiming it would be better if we could just let it all deform more as it rolled.

 

[jackmott]

Really? What lateral loads does a bike tire need to support? If you're laterally loading a bike tire, you're falling off. And where is all the structure in a bike tire designed to support a huge flat contact patch?

But independent of that, you're saying it's a curve between hysteresis and "impedance". There's zero evidence that even if a bike tire is in the trough of that curve at ~60 PSI that a car tire would be anywhere near that trough at usable pressures or compounds.

I am not claiming that the crossover point for optimum pressure of a car tire is anything like a bike tire. I have no idea what the crossover point is on a car, never seen anyone test that high.

What is the same for a bike tire and a car tire is that:

• Rolling resistance comes from hysteresis and impedance
• The more easily the material deforms, the less hysteresis you get
• You see this readily when comparing known low CRR car tires and bike tires. They are using thinner, more supple materials.