Forgot to mention that mpg is going to drop alot when cars done, car has a t5 and 2.73s in the back the tall gears are really annoying, going either 4.11 or 4.56 when the t56 shows up In my life. And yes horsepower and mpg when doNE correctly actually does = more mpg, because higher performance engines have a much higher volumetric efficiency have faster cleaner more complete combustion in a smaller combustion chamber think about that too, air fuel ratios must still be met, when you have a higher compression ratio your combustion area has less air volume ie requires less fuel, and that all comes into play that's why all the new motors coming out are back up to 10-11:1 compression, and the new v8s are getting respectable mileage AND making more power, look back to the 80s, an 8:1 350 with a cam that doesn't open the valves long enough to let it clear it's lungs? That's why those motors puked all over themselves lol