In reply to ttrmike:
After fifteen years of burning unleaded in a MSR XGK, I swapped to Aspen 4T as a treat to my new Primus Omnifuel. Much cheaper than Coleman, more expensive than petrol, harder to find.
Nice clean controllable burn, burns very well and bar the odd pricking of the jet haven't had to do any servicing in over a year.
Make sure you get the 4T version NOT the 2T.