Quote Originally Posted by Mullet Man
holy shit 110miles.....wow,think ill stick to domestics i get almost 350 miles out of my V8

And you probably have a 20, 22, or 25 gallon tank. O_o


Its a turbo 2 liter. And after reading up on Nico forums, some guys are getting 28 if your not on it. The average is about 23-25 on the highway if tuned right.
HybridZ guys use RB20's mostly for low-power daily drivers. Most of them can hit 30mpg highway, but that's out of a 2000/2400lb car fully loaded. Your WOT tune seems super rich, but if you're putting down 300whp then you might be over-stressing the setup to get that kind of power. That much gas might be necessary for that kind of setup with stock turbo. To be honest I'd get it retuned with 300hp as the goal, and if that still gives shitty power, get it retuned to be leaner where you can see what gas mileage is lower down. After that, I'd go with the basics to get more efficiency out of the motor.

This is all after you've done the dumb normal stuff. Plugs/wires/filters both air and fuel and so on.

Edit: Durr. Wait. I'm an idiot. You said it had an RB25DET, yet then you said it was a two-liter Turbo, is it an RB20DET or RB25DET? If you're only getting 300 to the wheels and terrible gas mileage out of an RB25DET you need to have that looked at. Something is bad.