Hi,

I went to baja california for a few days. My westy behaved great, except
that one day it started making a knocking noise. Sounded like a screwed
piston, really bad. But this guy told me that it was the mexican gas, so he
gave me a bottle of "octane booster" and after ten miles the noise was gone!
Everything went great.

My westy 84 went from San Francisco to San Felipe and back without a single
problem!!

Thought it could  be a good piece of info. Octane booster is sold everywhere
in different brands...