Only had mine for about a month now.
First tank got 35. Was driving it hard for the first week or so since it was new to me and was trying to see what it's got. I also live in a hilly area, (Santa Cruz Mountains).
Second tank got 37. After the second tank, I finally remembered to check the tire pressure. Found all four tires at 30 psi.
Topped them off at 40 psi and I'm still working on the third tank.
Also just loaded KermaTDI's stage 1 tune so we will see what that does to mileage. I am thinking if I keep my foot out of it,(LOL), it should increase the mileage.
These things get such good mileage it takes me a long time to check the mileage.