I honestly was not expecting anything too dramatic, my modifications consists of 155/30 injectors, 64mm turbo with 10 blade turbine, and stage 2 Callie's cam. But upon installation (which is super easy!) I was very surprised! Greater boost numbers, and boost that holds much longer from 3-5, along with egts reduced from 1400-1500 degrees down to around 1350 at WOT, which in itself is worth it! Fuel mileage hasn't really been a huge concern for me (I have a heavy foot) so I cannot really judge the product based on that, but I wouldn't be surprised if you gained a little bit! Overall I highly recommend the product!