Top Teir is a government standard. Which is not that great. The main thing that sets Top Tier gas apart from everything else is its additives, and Techron is the first and probably still the best of these.
If only people would read just a little bit more. Pictures are worth a thousand words, so, here is the summary: Click to see the TOP TIER Gasoline Brands. Notice that Costco (USA, Canda, Mexico) is a TOP TIER retailer. Crap, Chevron is a TOP TIER retailer too. What is one to do?
Top Tier gasoline brands, however, significantly exceed the minimum detergent requirements set by the Environmental Protection Agency (EPA). It is a standard set by 8 leading automakers. My point is that not all Top Tier gas clean the same. Some clean better then the minimum requirement.
Political speeches often have more than a thousand words. Therefore, LIKE PICTURES, they're always truthful. Just like the internet. Q.E.D. "Gas War" posts are a lot like "oil war" posts. Like all battles, they're mostly fought by young men, or by older men trying to recapture their youth. The reason that wars are not usually fought by women or older men is they generally have more common sense. Most of the gas snobs drive new cars that they trade out before 150,000 miles, so they represent (IMHO) the least informed about long term fuel related issues. Dirty valves? Really? I've NEVER EVER seen a Prius Chat post with somebody holding up a dirty valve or having to replace the top end of a motor as a result of a fuel related failure. I've NEVER EVER seen a Prius Chat post with somebody holding up a clogged injector. So... "Top tier" gas. It's all I ever use in my Prius, but that's because I have a company gas card and I really do not care how much the gas costs for this car. I lean towards the monster-mega stores because they have clean restrooms and a large selection of refreshments. Lately....for my personal cars I use mostly Murphy because I can reload a cash card and not have to worry about card skimmers and I'm never far from a Murphy store. I also have a Credit Union fake Mastercard attached to a disposable checking account for times that I have to use a "top tier" station or make an online purchase. For what it's worth.....
So, then, Top Tier is NOT a government regulation.......but an "industry standard". I personally think it is a marketing gimmick.......but that's just me. AND.....the government has nothing to do with what kind of oil that car makers recommend either. Except that thinner oil helps them make their fuel efficiency targets.
EPA standards come from the government. The Auto industry did not think it was good enough gas so they came up with Top Tier.