Re: Premium gas on a 2004, can it be changed?
Again, because of a brain fart, I accidentally tested regular fuel. Our knock sensors and computers adjusted to the fuel and the car ran fine. I experienced less performance and worse mileage. Because of the drop in mileage I believe you can't save money and in fact will actually spend more to use regular. A 10.5:1 compression engine is not going to run with the ignition at optimum advance on regular. Even if this did work without the negative side effects, you are only saving a couple of dollars per tank. If this is that important sell your Crossfire to someone that will take proper care of it and buy a Prius.