Originally Posted By: dave1251
Gas is gas. Have you heard that one before? Also there is a post on here that someone said the Costco gas was either Chevron or Shell supplied gasoline depending on your location. I have used it before and with no noticeable performance gains or losses. Do I use use more Top Tier gasoline than not yeah. But I have not noticed a difference between brands.
It's neither here. I'm fairly sure it's Exxon-Mobil at my local Costco.
I like Costco gas because it is cheap, high detergent, and higher octane. Around here most regular is 85.5 and premium is 91. Costco is 87 and 93. Lower octane used to be fine for carbureted vehicles in higher altitudes, but modern fuel injected cars compensate for atmospheric pressure. If your car calls for 87, you need to run 87, not 85.5