TOP TIER fuels are fuels that meet a higher standard of quality than traditional gasoline or diesel and contain detergent additives that keep engines running more smoothly and increase engine performance. Since automakers are unable to mandate certain regulations for fuel standards, the TOP TIER logo at a filling station is an indicator that the station offers fuel that goes above the traditional standards. TOP TIER fuel is available at most of the country’s biggest and most popular gas station chains, from Amoco to BP, Shell, CITGO, and Marathon to Sunoco, 76, and even Costco, just to name a handful of retailers.
Is TOP TIER Gas Worth It?
Invariably, there’s an ongoing debate about whether TOP TIER fuel is worth the added expense, and the truth is that high-octane fuel can help improve fuel economy and performance in engines that specifically require it. A study by AAA found that TOP TIER gas had a cleansing effect on vehicles fueled by it, with intake valve deposit buildup reduced by up to 72 percent over the course of driving 5,000 miles. Moreover, using an octane rating that is lower than what your engine requires causes some of the same drivability issues as using non-TOP TIER gasoline.
However, using high-octane fuel in a vehicle that is rated for regular unleaded will give you little to no benefit in most conditions. Furthermore, the cost of higher octane fuel even with non-TOP TIER gas is typically going to be more than simply buying TOP TIER gas with the right octane rating. Simply put, if your car’s manufacturer recommends TOP TIER fuel, then it is worth buying it for your car. Otherwise, it’s not a big deal to skip the TOP TIER pump and go for a more affordable grade.
Why TOP TIER Gas?
Most people tend to look at fuel prices first when they choose a gas station for a fill-up. Or drivers simply go to the station that's most convenient at the time. However, some automakers and plenty of experts recommend filling at stations that sell TOP TIER detergent gasoline.
It's commonly believed that all brands of gas are more or less the same. This is partially true. All gas is refined in the same way and it comes from crude oil. Gas in the United States is required to include certain additives to keep engines clean.
However, the TOP TIER gas brands do more than just the minimum requirements set by the Environmental Protection Agency (EPA). TOP TIER gas meets the more stringent standards set by some of the top automakers. It's a trademarked name derived from a program started in 2004. It was then that several automakers were concerned that EPA standards weren't strong enough to protect their new high-tech engines. TOP TIER gas uses a number of approved additives to reduce engine deposits and sticky valves.
Which Automakers Recommend TOP TIER Gas?
The list of automakers recommending TOP TIER gas includes some of the biggest and most popular names in the industry. European, American, and Japanese automakers fill out the list, which includes Audi, BMW, General Motors (GM), FCA, Ford, Honda, Toyota, Mercedes-Benz, Navistar, Volkswagen, and Detroit Diesel.
How To Recognize TOP TIER Gas Stations
There are a large number of well-known gas retailers that sell TOP TIER gas, including over 50 brands. You can recognize individual stations that sell TOP TIER fuel by the trademarked logo. It’s notable that though TOP TIER designation is a good thing to look for when choosing fuel, formulations are unique to each company but all are screened for TOP TIER standards compliance.
A list of licensed retail brands selling TOP TIER fuel in the United States as of 2021 includes:
Harmons Fuel Stop
Hawaii Fueling Network (HFN)
Kirkland Signature Gasoline
MFA Oil PetroCard 24
Simonson Station Stores
Tobacco Outlet Plus Grocery
Notably, only a few retail locations in the United States sell TOP TIER diesel fuel. Those that do sell diesel in the TOP TIER lineup include Co-op, Costco Wholesale, Fast Stop, Fast Stop Express, and Kirkland Signature.
Remember that using TOP TIER gas has nothing to do with the octane ratings. If a station sells TOP TIER gas, then all of its gas grades should be TOP TIER quality.
Does It Cost More?
While many people assume TOP TIER gas is significantly more expensive than regular fuel, that's often not the case. In general, fuel prices tend to depend on area and competition. The AAA estimates that TOP TIER gas costs on average about three cents more per gallon than non-TOP TIER.
What Does TOP TIER Gas Do?
According to the organization behind TOP TIER gas, the enhanced fuel helps reduce harmful carbon deposits on an engine's fuel injectors, intake valves, and combustion chamber. These deposits are caused by fuel that doesn't burn.
TOP TIER gas can also clean engines that previously used non-TOP TIER fuel. Due to its cleaning power and more efficient makeup, TOP TIER gas can both increase fuel economy and improve emissions.
How Does TOP TIER Gas Work?
Research from AAA showed that the average engine using TOP TIER fuel has 19 times fewer deposits on its intake valves versus those on an engine that's been using regular fuel. The AAA study also showed that using regular fuel can eventually reduce fuel economy by as much as four percent.
Deposits from unburned fuel can also cause drivability issues. Some symptoms include idling rough, hesitation or stumbling, reduced fuel economy, and a knocking engine. Engine knock in particular can be damaging. In a smooth-running engine, the mixture of fuel and air is precisely controlled so that it ignites exactly when it's supposed to during the combustion cycle. This cycle is what causes the pistons to depress and turn the engine. If combustion happens too early, then the force will run into the top of the piston during its travel up the cylinder. This creates a knocking sound and, with enough repetition, it can cause serious damage.
AAA's fuel quality research looked at a clean valve, a valve on TOP TIER gas, and a valve on non-TOP TIER gas. The non-TOP TIER valve showed sludgy black deposits on the bottom of the valve, and the entire part had a dingy look compared to the TOP TIER valve and the new valve.
Can I Just Use Higher Octane Gas?
As previously mentioned, TOP TIER gas has nothing to do with the octane rating. Ostensibly, octane ratings do have a relationship to a fuel's ability to resist knocking during combustion due to premature detonation. However, these ratings are very much related to specific engine types. Engines with superchargers or turbochargers and engines with higher compression ratios typically need higher octane gas. This is because more air is being forced into the engine. More air means that the engine can take more energy from the air/fuel mixture, but it can only do this if the fuel has more octane to prevent it from detonating too early.
Keep in mind that TOP TIER fuels have nothing to do with the fuel’s octane rating. All fuel marketers participating in the TOP TIER fuel program are required to provide TOP TIER fuel for all gasoline and diesel octane grades at their participating stations. Regardless of a vehicle’s pre-determined octane requirements, TOP TIER fuel is formulated to automakers’ standards for cleanliness of engines in all vehicles. Automakers recommend TOP TIER fuel to increase customer satisfaction, minimize emissions, reduce downtime, and increase vehicle longevity.
It’s important to note that TOP TIER fuels are not the same as premium fuels. Premium fuels are of the required grade recommended for vehicles with performance engines that have higher compression ratios and may incur damage from the use of low-octane fuels.
The takeaway here is that if your car requires you to use TOP TIER fuel, by all means, do it. If, however, the manufacturer of your car doesn’t require TOP TIER fuel, it’s not really necessary to go the TOP TIER route at the pump.