I fill up with 98ROZ when I can, which is almost every time. I've only used 95 once, and just because I was running out of fuel. My parents regularly run their 997C4 on 95, without any problems.

I thought Ethanol was a big concern so I'm only using Shell Vpower 91 (only non ethanol in Canada) and adding STP octane boost per tank ...

91 Ethanol free gas in Lakewood, Colorado, not sure how effectively 93 would burn at high altitude or if it would improve HP at high altitude 5280+ in elevation

Chevron 91 and or Shell. The car seems to adjust to the lower rating without issue. It would be nice to try 93, for a couple of tanks, to see the difference.

The label on my fuel tank door says to use only 98 petrol . Thats what I put in , we have BP 98 Ultimate here its about $2.10/L I think .

I do the same. Shell is the only one (I am aware of) who doesn't have ethanol in their top octane product. I give it a shot of the octane boost per tank as well, it seems to like that.

Chevron...use shell if low on fuel and no Chevron around.

Shell...Shell......Shell....Shell yeah!!!
 

Shell V-Power.

Join their loyalty program and get 5 cents a gallon off every fill up.

:cheers:

I fill up across the border at Texaco. Texaco is owned by Chevron, and has the same additive package in their fuels - Techron.

I know a guy in the industry and he says all base gasoline is the same. It's the additive package that distinguishes one brand from the next.