In my 88 GXL I would usually get about 220-250 miles out of a tank of gas before I would fill and the needle on the gauge was usually around 1/8 a tank. In my TII the mileage is noticeably worse, but not as bad in fact when I went on a road trip to my grandparent's I got 350 out of 16 gallons or so, with some boosting on the highway and showing off my car to my family.

I'm pretty happy with those numbers, in fact I need to replace the O2 sensor in my GXL before I sell it and I have a sneaking suspicion that my precat in my TII is starting to get clogged.

With my 88 T2 BM's (Before mods) I was getting about 18 MPG now with my Bonez MP & DP & single exhaust, I am getting around 15 MPG. More boost = more fun & less MPG! And this means for more fun I need more "funds" ha ha...

I have a 90 GXL with a street port, and I did see my mileage drop once the porting was performed. It has seemed to always get bad mileage though... I get about 140 KM's for 20$, (Can.) and thats at about .70$ a litre or so.... so 140KM for 28.5 litres... I can't remember how many litres in a gallon... crap.... Oh well, I know it's Sh*t!!!