Originally Posted By: rhhsiao
Originally Posted By: FastGame
Originally Posted By: Apollo14
Costco gas is probably the best out there. And it is often the cheapest.
Just have to put up with queues sometimes.
Really ? and who's gas is Costco pumping ? If they are the best it would only be that they sell a lot of gas so it's always fresher than other stations.
All the random test I've read say Shell and Chevron are the best, most consistent additive wise....very closely followed by Mobile, BP, Texaco. Very little between the top 5 except that Shell and Chevron are said to have best additives.
Who's gas Costco pumping ?
Originally Posted By: badtlc
Sunoco says its fuels "significant exceed" minimum EPA requirements. It is likely Sunoco is at or above Top Tier requirements. It might be as high as BP and Shell but I wouldn't avoid Sunoco at all.
All the Sunoco's I've seen in Michigan say Invigorate® on the pumps, wouldn't that be BP gas ?
Costco gets its gas from local suppliers/refiners just like every other station (gasoline is a commodity good) and meters out the additives at the station itself.
Of course the base fuel is a commodity. I know there's the loyal Shell/Chevron/Mobil/etc customer who wants to be believe that the name at the pump means that the fuel came from a refinery with the same logo, but that's just not the case. Most fuel goes through pipelines to the fuel depots and gets intermixed with the fuels from different refineries. The refiners set standards, and when they trade - you better believe their trading partners will keep them honest by testing the fuel to make sure it meets the standards.
A few years ago, the Chevron Richmond refinery lost most of its output after a fire. Chevron stations didn't suddenly put up "no more gas" signs. Chevron just bought fuel on the commodity market to supply their stations. I think that normally their inputs to the fuel depots count as credits that they use to supply their retailers.
The big deal should be the maintenance at individual gas stations, and that's often dependent on the willingness of the franchisee. However, that's supposed to be tightly regulated in California. CARB does random checks at refineries, depots, and gas stations. They have a mobile testing lab that can check for octane rating, content of fuel/ethanol, water, contaminants, and other issues.
As far as Valero goes, they're one of the top 3 refiners in the US in any given year. It's highly likely that drivers in certain parts of the country have used some of their base fuel, although it might be mixed with fuel from other refiners.