ChadR33: Try running Shells 98RON fuel.
I threw a tank of BP Ultimate in mine, and it did nothing but misfire, fart cough, popped a flame or two also (When using gears to hold me back) and I got pretty shit economy from it.
I have so far found the Shell fuel to be the best (Have run Caltex, BP, and now Shell)
Also, someone on here mentioned, if you keep the revs below around 2500RPM when accelerating, fuel consumption drops majorly, but get much above 3000RPM, and the fuel will be used the same basically as if you rev out to like 5500RPM each gear.
Hence, I cruise mine, keep the revs down, barely touch the throttle when accelerating.
So far this tank (nearly 200KM) I've only hit boost once, and that was only 5PSi (My "low" boost is around 7-9PSi) and that was coming down a short freeway onramp from like 20km/h, and needing to get up to 100km/h to merge into traffic.
Normally I sit along way in vacuum even when accelerating (5mmHg is normally my "fast" accelerating vacuum)