I have 1 mod on my 2000SSEi. That is a 3.4 pulley. 2 step cooler plugs were installed. All work was done by Intense. Will the cooler plugs effect gas milage?

no, but the foot on the pedal will.

gas mileage is the least of your worries, the feeling of needing to handi over stacks of cash to Intense is you biggest worry now.

I have the Intense 3.4 pulley also, but only went one range cooler on the plugs. I have not noticed any significant change in the gas mileage. As Travis said, you have 2 problems now. Trying to keep from using that extra boost, and once the mod bug gets you...keeping your money in your pocket. If you drive the same as you used to, you won't see a change in th mpgs.

If you're like me and almost everyone else here though, you wont drive the same.

Your car should whine more now, and this will encourage you to mash your foot down farther and farther. This oddly enough, results in decreased gas mileage.

But as was said, you should get about the same if you drive the same, in fact, you might even get a little better.

your driver info will also let you know if your loosing mileage, I went down a couple of points with the extra weight on my car.

Moved to General Chat. This isn't a mechanical problem.