“For now, we have to operate at the limit of what the car itself is capable of,” explains Finke. “The E-tron was built on our MLB Evo model architecture, the same one that the Audi Q7, Audi Q5 and Audi A6 all use, so the chassis and axles simple aren’t designed for greater cross-axle loadings than the ones that we’re already working with.”
As it is, says Finke, the E-tron S Sportback’s rear axle will never actually put negative torque into the inside rear wheel while driving the outside one: “We would have liked that capability, but since we can simply use the ESC to brake the inside wheel, we aren’t entirely without it. Yes, we could probably produce some handling gains if we had it. But to deliver really big gains, you would need a car with a purer sporting brief than an SUV – something lower, lighter and stronger-bodied, designed from first principles for dynamic handling.”
Inherited ICE car platforms are clearly one of the technical reasons why EVs aren’t yet showing the greatest torque-vectoring gains, then, and at least we know that won’t be a problem forever.
“You would also need a battery capable of really fast regen and much finer control of that regen if you wanted to do more with electric torque vectoring,” says Finke. “When you have that, maybe you won’t even need friction brakes any longer.”