I don't remember seeing anyone posting up the gas milage that they are getting after getting supercharged. I figured I'd post my findings for those that are contemplating going the same route so they know what they are in for with the current gas prices we are faced with.
Before I installed the SC I guess I was averaging around 20mpg with mixed driving (calculated by on board computer), after the SC was installed the computers numbers are far skewed by the larger injectors installed with the kit. Currently my average shown on the dash is around 30-32mpg .
Hand calculated milage for my last tank of fuel was 17.5mpg with a good mix of highway and around town driving as well as a few blasts of the right pedal to "blow out the cobwebs"... so I'd say very livable milage for a modded car. I'm sure if I stepped on it more that number would drag down to 10-12mpg. I think you can actually watch the needle move when you get into the boost..

I'd also like to report that after 7k miles with this kit, it has performed flawlessly.

 

i'm averaging about 14mpg mostly local driving with 30 miles stop n go traffic everyday. getting 220 out of the whole tank max.

 

Mike thanks a lot for this review. I was on the fence between the GTM TT and the SC, but after assessing the costs of the TT kit, I think I'll be getting the SC instead. And with this new stage 2 that Sam at GTM is cooking up, the power difference between the two should be minute.

 

Sounds about right... I'm sure I'd be right there with my highway milage taken out of the equation.

 

I know my kit is not a GTM but thought I would post my results for comparisons sake. My last 3 fill ups were 12 mpg. My commute is 100% city, light traffic but all stop and go (10 to 13 stop lights and stopsigns depending on which route I take) with a total one way commute of 5 miles. I was averaging around 14 to 16 for the same route prior to installing the kit. I have not had any highway crusing that was not in heavy stop and go traffic since I got the kit but I hope to get some in this summer.