Has anyone tried this in their Scoobs....

Apparently in Oz it is the big thing for increased power / approx 25% and 30% better fuel consumption

Anyone know how to get hold of some/// also will it destroy the cat?

Butyl methylate? Sure they weren't referring to MTBE http://scifun.chem.wisc.edu/chemweek/mtbe/mtbe.html

Kerosene is also Jet A fuel as used in airliners. Basically paraffin and pretty dirty stuff with a low octane rating - would probably kill catalysts.

Might be ok in your 1954 little grey Ferguson tractor, but in an Impreza, hmmm......

Easiest way is to wire up an extra injector to spay alcohol or water directly into the inlet manifold gives you similar performance gains, and stops you melting pistons at the top end.