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What is Top Tier Gas?

By Autolist Staff | February 11, 2019

Top-tier gas is not the highest number on the fuel pump, but rather it is gas manipulated with additives and detergents to help your engine run more smoothly.

What Is 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 gas.

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 U.S. 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 EPA. Top-tier gas meets the more stringent standards set by some of the top automakers. It's a trademarked name that is 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 is as follows:

  • Audi
  • BMW
  • Fiat Chrysler
  • General Motors (Chevy, Buick, GMC and Cadillac)
  • Honda
  • Mercedes-Benz
  • Toyota
  • Volkswagen

Navistar International, which builds commercial vehicles, also recommends top tier gas in its vehicles.

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. A list of brands selling top tier fuel includes:

  • 76
  • Aloha Petroleum
  • Amoco
  • ARCO
  • Beacon
  • BP
  • Break Time
  • Cenex
  • Chevron
  • CITGO
  • Conoco
  • Co-op
  • Costco
  • CountryMark
  • Diamond Shamrock
  • Entec
  • Esso
  • Express
  • Exxon
  • Holiday
  • Kwik Star Stores
  • Kwik Trip
  • Mahalo
  • MFA,
  • Mobil
  • Ohana Fuels
  • Petro-Canada
  • Phillips 66
  • PUMA
  • QT
  • Quik Trip
  • Road Ranger
  • Shamrock
  • Shell / Shell V-Power
  • Sinclair Standard
  • SuperAmerica
  • SuperFuels
  • Tempo
  • Texaco
  • Tri-Par
  • Valero

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. Most notably, ARCO and Costco are known for reasonable fuel prices. 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 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:

  • Rough idle
  • Hesitation or stumbling
  • Engine knock
  • Reduced fuel economy

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, can cause serious damage.

AAA's fuel quality research photo shows a clean valve, a valve on top-tier gas and a valve on non-top tier gas. The non-top-tier valve shows sludgy black deposits on the bottom of the valve, and the entire part has 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.

High octane gas helps performance and fuel economy in engines that require it. Similarly, using an octane rating that is lower than what your engine requires will cause some of the same drivability issues as using non-top tier gas. The main difference is that 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.