Joel85

I have an '05 xr6t with 65,000 on it. Fuel consumption is about 13.5 - 14.5l/100km around town and gets down to about 10.2 on the h'way. It doesn't like any fuel other than BP Ultimate 98, is there something wrong with it??? Also, with a full tank I can't use any boost because it just feels like it's going to die until it gets down to about 3/4 of a tank then it goes back to normal. Any suggestions on why this might be?