Was pleasantly surprised yesterday when I filled up at the pumps. The results were 27.24 mpg which was similar to the last fill-up. While this may not seem all that great to some... this tank as the last was mostly full throttle joy rides with my latest mods.
My son took it out to show some of his friends and I also did several demos for a few friends who are thinking of getting one. So I am quite pleased with the performance vs mileage..
My MPG before mods was about the same... even with the less agressive driving style.. Good stuff..

 

+1, my milage improved after doing the 15% reduction.

 

My understanding of most simple engine modifications is that it has the ability to increase gas mileage, but generally won't. Usually things like an air intake and an exhaust allow the motor to breath easier, and in return they are able to make more power with less revs... meaning better gas mileage. This usually is cancelled out by the right foot though, as you now want to drive it harder and don't see the MPG go anywhere but down. :-P

I am hoping to get close to 30mpg with my S when it comes in. I do a lot of highway type driving and hopefully I can keep my foot out of it at those times to get better mpg.

Drew

 

factory JCW car, and we see approximately 27-28 mpg, mostly city driving. . .

\although it doesn't get much better on the highway exclusively, we rarely have topped 30 mpg, even on the long drive up to the dragon. . .

 

This is true... When you make the engine more efficient you get more power with less fuel. The MCS is setup to run rich from the factory. Running rich helps keep detonation in check but also makes for lousy mileage.
I was surprised to see the mileage remained the same with the extra power I am now making. These mods create a big difference in power... and I am told by the experts... are safe and maintains a safe AFR.