A friend of mine has a late model GMC Yukon and he says he gets better gas mileage with the traction control off than with it on. 19mpg vs 18mpg. I think it because the traction control system is applying the brakes, ever so slightly, like on curves and turns etc. Does that make sense?

 

i know that when the traction control on my Sierra kick in, there is an icon that illuminates on the instrument panel. Its usually happens when there is full wheel spin like when i nail the gas pedal turning a corner.