Standard vs Low regen and rear tire life?

[Luis Mengual]

Dear all, let me expose my humble opinion about this amazing thread; giving as base, this car is 4.600lbs 46/54 weight distribuition. (Heavy and powerful rear axis Vs narrow 245 sport tyres is a fact, despite 265 of + series)

-In acceleration stages, this weight change even more to rear axis, burning exponentially as press the right pedal by friction, hysteresis and drift of tyres onto the asphalt.

-Decelerating this weight change forward but assuming that only is retaining rear wheels most of the time, wear tyres by the same principle as accelerating. Stressing 80% rear axis vs 20% front axis only by accelerations/decelerations.

-Incorrect/flexible toe (which is most of Model S), incorrect tyre pressure and sport ride style will increase this degradation suddenly.

Things that can be done to improve this issue:

-When I wear sport tyres, I warm up them by low power delivering and gentle turnings before sport riding.
-Monitoring pressures every 1k or 2 weeks, and inflate with nitrogen (will help to maintaing this pressures)
-Suggest to service, inspect and modify Toe clearance as tight as possible. Notice that when you have more than 2º rear camber you must compensate with slight toe, but if this toe is out aligned or too much mechanical clearances when accel/decel, forget long life.

Conclusion,
Style of riding and proper care and maintenance will help to prolongate tyres life... Sorry for this brick,

 

[Luis Mengual]

Regarding Low/Standard regen, of course you can save tyres, but maybe only some hundreds of miles of its life with low Vs std regen, also Low regen feature will help in terms of battery and HVDC plant health (cicles, heating, etc). In the other hand, with low regen you´ll pay obviously with less range due to less regen energy, and burn front brake pads.

Which is more beneficial? Low or Standard... For me, combined could be the best sollution, depending type of trip and driving style.

 

[jerry33]

Given the same driving style you're going to have a combined tire wear rate that's the same whether regen is low or high. The only difference is going to be whether the wear bias is on the rear or not. (Of course, if most every start is a rocket launch, the rear is going to wear quickly regardless of any other factors.)

 

[slcuervo]

So, the conclusion is that tire wear (especially for the rear tires) depends on how you drive, and not on having regen braking high or low.

 

[Freeride]

But why wear on rear tires? I thought the two regenerating engines was mounted on the front tires. Am I totally wrong?

 

[brianman]

But why wear on rear tires? I thought the two regenerating engines was mounted on the front tires. Am I totally wrong?

1. There are no engines.
2. There is one motor, and it's in the rear. This motor is responsible for both consumption and "regeneration".

 

[Freeride]

Thanks for the clarification. I guess I've understood the regenerating system all wrong from day 1.

 

[jerry33]

Thanks for the clarification. I guess I've understood the regenerating system all wrong from day 1.

One of the most common misconceptions I encounter is that there is a motor in every wheel. You're not alone in not grokking how the Tesla drive train works, so don't feel bad.

 

[Luis Mengual]

One of the most common misconceptions I encounter is that there is a motor in every wheel. You're not alone in not grokking how the Tesla drive train works, so don't feel bad.

+1,

 

[brianman]

One of the most common misconceptions I encounter is that there is a motor in every wheel. You're not alone in not grokking how the Tesla drive train works, so don't feel bad.

+1

I also get a lot of in-person "huh?" when I inform people that they are wrong when they casually assert that the Model S is AWD, or FWD.

 

[UberEV1]

Another potential reason for greater rear tire wear could be the open differential design, which I believe uses differential braking to modulate torque to the rear wheels. Combined with the fact that regen is only generated from the rear wheels, the two conspire to wear out our rear tires faster.

 

[maximizese]

Bringing this back from the dead because I'm not satisfied with the conclusion some have drawn.

First off, that's an interesting theory about the open differential with braking to modulate torque. But to address the question, the standard regen setting would most likely wear out my tires faster than setting it on low regen. In my case, I find the standard regen to be too jerky and I've always been an early and light brake applier. I've had cars that have gone over 250K miles on the original clutch and brake pads. It is very rare that I see the power meter go below -40kW (while regenerating). To transition into a more aggressive regeneration every time I lift-off the accelerator would make a lot more friction that I desire....but I'm also someone who gear coasts in top gear and glides in neutral while driving a manny tranny.

I can't believe how many folks are seeing ~8K miles of life on their tires. At that rate we'd be going through 3 sets of tires a year. I should note that we have a 2013 MS 85, maybe the absence of a P and D signals that I'm no longer ga-ga about speed.

 

[deemo]

2. There is one motor, and it's in the rear. This motor is responsible for both consumption and "regeneration".

I also get a lot of in-person "huh?" when I inform people that they are wrong when they casually assert that the Model S is AWD, or FWD.

Most Model S's are AWD (designated with xxxD's) - with motors on both axles and both being used to propel and regenerate/slow the car with the motor/generator. The original post was for a non-D but you are leaving the impression that all Model S's are RWD.

 

[brianman]

you are leaving the impression that all Model S's are RWD.

That's one interpretation. Not one that I agree with though. English is apparently a language that is misinterpreted more often than interpreted correctly.

 

[brianman]

Most Model S's are AWD

Link to the data? I'm not sure that's true for Model S yet.

 

[ucmndd]

The rear tires on my RWD MS absolutely wear much faster than the fronts. I've always attributed this to them doing 100% of the acceleration and a good 90% of the braking. There seems to be some truth in that as AWD "D" owners tend to report more uniform tire wear. Setting regen to low and transferring most of that braking duty to the front wheels and brake pads would certainly seem to reduce wear on the rear, but I'm not convinced of the value of making that decision - losing considerable efficiency to have tires maybe last a couple thousand more miles.

 

[sorka]

So, I don't have any experience, but my thoughts are - you're going to slow down when you want to slow down whether you're on standard or low regen - it's just a question of whether that energy goes into the battery or the brake pads. So I wouldn't expect any significant difference.

The difference is that on rear wheel drive, 100% of regen braking goes to rear tire contact patch vs most of brake pad braking going to the front wheels which tends to balance out tire wear front vs rear on rear drive only cars.

 

[David99]

But to address the question, the standard regen setting would most likely wear out my tires faster than setting it on low regen. In my case, I find the standard regen to be too jerky and I've always been an early and light brake applier.

This is what I just don't understand. When accelerating, no one ever complained that it's 'too hard' or too aggressive. We are all perfectly capable of pushing the pedal the amount we want to get smooth and gentle acceleration. When it comes to regerative braking, using the same pedal in the same way all of a sudden doesn't work any more? That makes zero sense. If you can modulate the pedal to get half acceleration power, you can do the same for regen.

I will admit that it took me a day or two to get used to the one pedal driving, but since then I have never even thought about it in the last 5 years driving my Tesla. It's just so natural. I'm perfectly capable to adjust the deceleration with the pedal to match the traffic situation. It makes no sense to me to limit the regen power using the 'low regen' setting. I can get lower power regen just fine by keeping my foot on the pedal, just as much as I can get smooth and gentle acceleration. Often I want to decelerate quicker and that's when I use the full range of regen.

The complaint that regen is too strong in the standard setting comes from people who have it in their DNA that every time they don't want to accelerate, they take the foot off the pedal completely. It's years of muscle memory driving ICE. Keep the foot on the pedal just where it is. You can adjust regen power perfectly accurate to what you need in any situation. Embrace one pedal driving. Let go of the old ICE habit.

The only time I switch to low regen is on ice roads. Standard regen can cause the wheels to lose traction and make the car slide. For very slippery roads I actually wish there was a zero regen option to get zero torque on all wheels in situations where the car is sliding.

 

[linkster]

I am with @TsRocket in that one can choose to transfer your tire rubber to the road surface or keep the tire monies in your pocket, and I agree with @David99 that it may be useful to modulate the regen with your right foot. I believe modulating (I regen on normal and modulate at ~ 30kW) is especially important on RWD with 21s. I deploy said technique (1 of several) to help achieve 51,000 miles with 3.5 tire rotations from original 21 Contis. I am currently on my second set of Conti 21s (but now staggard) with 85,000 on the S with the same projected tire service life as the original set.

 

[Brass Guy]

For very slippery roads I actually wish there was a zero regen option to get zero torque on all wheels in situations where the car is sliding.

You could let the car cold soak.
If you need absolutely 0 torque, slip into N. I used to do that if I started slipping in a manual transmission car; even light engine braking exacerbated the problem. If you're over 5mph, you don't need to touch the brake to put it back in gear; just be mindful how you press the accelerator while re-engaging D. I can usually do it very close to 0kw with a light press.

For a RWD car, standard regen will wear out the rears slightly faster than when on low. With regen on low you'd be using the brake pads, causing slightly faster wear on the front. Overall, the difference in wear would not be measureable. Rotate your tires as recommended, and recoup as much energy as you can instead of dissipating it off your brake rotors.