Here in Colorado it is nearly impossible to find fuel with octane any higher than 91. There are a couple of places with 93, but they are few and far between. When I had my truck I was told by a reputable Ford technician that because of our altitude we could run at the lower octane with no problem but I don't think this would apply to a turbocharged car. Mark has done some high altitude Unichips for JaMa and Nmyeti. Maybe they can fill us in on the fuel requirements and what he did for their mapping.
Punk