I put a powerchip in my 300CE, it affected smog, illegal in CA. The performance gain is all up top, feels a bunch slower on takeoff and such, but I also got better gas mileage, mostly for supercharging, if its all you're going to do to your car, dont do it. Course, it might be different on a V8. OH, unless sound is a real big deal to you, it is for me, makes the car sound super cool. Louder, but not too much, and not tacky broken muffler, Mower sound.