There are a few locations that are very near to me where I can purchase gas. Most are gas/convenience outlets, but there are still a few that have actual service bays and perform maintenance and repairs. The station that I had hoped I’d developed a relationship with for service over the last 5-7 years had let me down one too many times recently, so I found myself looking to establish a new relationship with the other ‘full-service’ Liberty-branded station nearby. As I stood by while filling up with gas the other day, I realized that the pump was missing something that I thought was ubiquitous; the sticker that describes the ethanol content. I then looked at all of the printed materials and posters up around the station, and didn’t see anything referencing the quality of the gasoline. This got me curious, so I decided to do some research when I got home. The entirety of the information found at the Liberty Petroleum web site was for the benefit of the owner/franchisee, and not a retail customer like me. I started to get a bit concerned, so I poised my question regarding product quality to the Liberty Petroleum Facebook page, and so far have not received a response.

Searching online for some source of information regarding gasoline quality, I stumbled upon a term I’d never heard before; Top Tier Gasoline.
WTF is Top Tier Gasoline? I had to look it up, and instead of me trying to clumsily explain, I’ll just quote this clear explanation from Carfax:

“...Top tier gasoline may help reduce the build-up of ‘gunk’ in the engine which comes from impurities in gas. These are broken down by adding high levels of detergents to the fuel. Top tier is also free of metallic additives, improving its quality. It is usually slightly more expensive than regular fuel, but only by a few cents per gallon. It was developed to protect the engines of cars with fuel injection technology. During the 80s and early 90s car manufacturers were reporting that the engines of cars with direct fuel injection were getting clogged with gunky build-ups, originating from impurities in gasoline. As a result, the Environmental Protection Agency (EPA) started regulating minimum levels of detergent that need to be present in gas to break down impurities, with the idea of improving fuel quality. Unfortunately, some suppliers reduced the amount of detergent in their gasoline to the specified minimum, reducing the overall quality of fuel available instead of increasing it. In the early nineties some of the world’s biggest auto manufacturers including Audi, BMW, General Motors, Mercedes Benz, Volkswagen, Honda and Toyota set higher benchmarks for top tier fuel. In order to brand their fuel as top tier gas, retailers must ensure that is has two to three times more detergent than the EPA minimum, which combats gunk build-up, and is free of metallic impurities which damage vehicle’s emission-control systems...”

So apparently, my perception that premium gas from any supplier was higher in detergents and additives was not necessarily true. Not only are all gasolines not the same in the obvious ways, but there’s this whole gas quality paradigm I was completely ignorant to. It also makes me wonder if there was any cause/effect because the major gasoline retailer that I had used near exclusively for my ‘06 MDX is NOT on this Top Tier Retailers list, and at 105K miles I ended up needing both cylinder heads overhauled/rebuilt, even though I use synthetic oil exclusively and change it every 5-7K miles. And through that experience and throughout my ownership of my Acura, no one has ever broached the subject of gas quality, and specifically the whole Top Tier concept, with me.

Now I’m not sure about any claims for increased performance, and surely the old adage “results may vary” applies, but it’s nice to have the knowledge and be able to make an informed choice.