Honestly it is very hard to say. I'm still having trouble with idle and hesitation until the car is warm. But, once warm, the car does seem to respond a bit better to the accelerator. The performance may not be that much of a gain, but I figure if I'm paying today's prices to put in premium fuel, I'd like to get all the performance form it I can. Once can get the car running properly from cold on, I'll try it with and without the resistor installed.