Traction control questions

Traction control questions

Can someone explain traction control to me? What does it do? How does it work? Does it affect range? Is it standard or part of an optional package on the car? Thanks everyone!

Electron | 2 novembre 2012

Think of it like the counterpart to antilock brakes. The computer will adjust power, power ditribution between the wheels and the brakes to ensure the wheels do not slip under acceleration. Similarly, but more complicated, stability control adjusts the same parameters to ensure the car does not spin. Both are standard safety features. They do not affect range.

Electron | 2 novembre 2012

"Distribution" not whatever I typoed.

dahtye | 2 novembre 2012

What's really interesting is that the Model S traction control is much better than any ICE car's traction control due to the tight control loop between the wheels and the drive train (including electric motor).
The control loop is described as: a sensor detects wheel slipping and feeds that information to the motor. The motor reacts by reducing torque to the wheels.
On an ICE vehicle, the gas engine cannot respond quickly (maybe a quarter second) then the torque change needs to go through the transmission - maybe another 100 milliseconds.
In the Model S, the torque change is almost instantaneous. There is virtually no lag between when the sensors detect wheel slippage and then torque is reduced.
This is why the traction of the Model S is so much better than any other car.

gary.greene | 3 novembre 2012

Thanks for the awesome, technically descriptive answer. I learn so much from my fellow Teslaholics on the forum!

Timo | 4 novembre 2012

It's actually a bit more than just drop the torque with the electric motor. Motor torque is done via adjusting the frequency of the sine wave and current and both are done by computer that does the calculations several thousand times / rotation of the motor. If needed it can apply negative torque to kill the inertia of the motor.

That's something that is way beyond anything you can do with ICE engine. It reacts way faster than you can perceive. What imprecisions there are are caused by sensor inaccuracy IE. car doesn't necessarily know when tires are slipping.

ChasF | 4 novembre 2012

And the advantages of EV just keep piling's like a perfect storm. I love it!

Volker.Berlin | 4 novembre 2012

If needed it can apply negative torque to kill the inertia of the motor. That's something that is way beyond anything you can do with ICE engine. (Timo)

ICE car uses brakes to achieve the same. Not as elegant as with the electric motor, and likely not as sensitive as with an electric motor, but it's not like the electric motor as invented traction control...

atsunset | 4 novembre 2012

You will want to leave it on!
Otherwise you will look like a kid in front of the auto shop.
Two wheels spinning and a blue smoke cloud behind you!

I had to try it…

DouglasR | 4 novembre 2012

I think it was in the Motor Trend article that they tested the Model S and BMW M5 both with and without traction control. If I recall correctly, traction control had a markedly negative effect on the performance of the M5 but made no difference in the performance of the Model S.