In the States: Mobil. I don't know, with my old Jetta on Mobil 93 it just felt a lot less anemic.
In Canada: Petro-Canada. They add fuel additive to their gas, in the summer Tractrol to keep engine clean and in the winter they have "winter gas" which has something in it to avoid fuel line freezing. Also, I have a credit card thru them that gives me 5.5c/L off and I earn points on all my purchases and bonus points when I fill up with 91 that I can then use on Amazon.com.
In Canada: Petro-Canada. They add fuel additive to their gas, in the summer Tractrol to keep engine clean and in the winter they have "winter gas" which has something in it to avoid fuel line freezing. Also, I have a credit card thru them that gives me 5.5c/L off and I earn points on all my purchases and bonus points when I fill up with 91 that I can then use on Amazon.com.