I'm not sure what the exact MPG is with the turbo, it's not too bad but it's noticably lower. Still stock internals, all about the tuning. This setup was dyno tuned with Hondata the day it was put in. 7psi is the highest this motor will see with stock internals. Jan's Type R has been running over 2 years on stock internals at 10psi if I'm not mistaken. This car does not get beat on. I get yelled at by friends when I'm driving about why I don't boost just for the heck of it. This car has seen nothing but 93 Octane since I purchased it. I bought it 2 years ago completly stock with 42,000 miles on it from a 49 year old hospital executive with 2 kids. He purchased it brand new and it still has all the oil change receipts in the glove box and judging from the mileage recorded on each receipt, he drove this thing like 6,000 miles the last year he owned it. Something tells me he didn't race or beat on it much either.