Gasoline Quality Differences

We constantly receive questions about whether there is really a difference in the quality of gasoline. With a gas station practically on every corner, prices from low to high, advertising all saying that their gas is the best - it's not surprising the confusion that results.

The short, yes there is a difference. So, how do we know what the differences are and what we should or should not buy.

It's not common knowledge but there are different standards for gasoline, Top Tier (Tier 1) and Tier 2. Top Tier is what you should use when possible. Six of the top world car makers (BMW, GM, Honda, Toyota, VW and Audi) recognized that the current EPA minimum for gas detergents did not go far enough to ensure the best engine performance. This group of car makers have raised the bar for gasoline detergents. This helps drivers avoid gasoline that will cause carbon buildup that will eventual harm the engine or at minimum hinder performance. Over the past few years refiners and the EPA have lowered the required amount of detergents and additives by almost 50%, this standard helps drivers stay clear of this lower standard.

What this means to you;
As you drive your car, your engine burns gasoline. This fuel travels from your tank by means of an electric pump, through fuel lines and filters up to the fuel injectors. At this point, the fuel is sprayed under high pressure into the engine through cylinder head valves.
This long journey from the tank to the engine has a couple areas where low grade fuel can eventually cause harm or problems. Its not uncommon for a higher mileage engine to suffer extreme engine performance problems due to carbon build up. This build up in the fuel injectors can starve an engine for fuel, lending way to hesitation, hard starting and poor fuel economy. Repairs can be expensive. Even worse, carbon build up on intake valves can also give these same complaints. However, cure for this situation (if severe) can sometimes involve disassembly of the engine to clean the carbon build up. You can see now how using a gasoline with the proper level of additives is very important!

Below you can find a list of currently known retailers that adhere to the strict standards of Top Tier Gasoline. You can rest assured that all grades and all locations that sell these brands must follow these strict guidelines.

The following text is a press release straight from GM in 2005:

This information applies to all 2005 and prior General Motors passenger cars and trucks (U.S. and Canada only).

Top Tier Detergent Gasoline, a new class of gasoline with enhanced detergency, will be appearing at retail stations of some fuel marketers. This gasoline meets new, voluntary deposit control standards developed by General Motors, BMW, Honda and Toyota.

The U.S. EPA requires all gasoline sold in the U.S. to contain a detergent additive. However, the requirement is minimal and in many cases is not sufficient to keep engines clean. A higher level of detergent is needed than what is required by the EPA. Top Tier Detergent Gasoline exceeds the detergent requirements imposed by the EPA.

The four corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies.

All vehicles will benefit from using Top Tier Detergent Gasoline, which will help keep engines cleaner than gasoline containing the lowest additive concentration set by the EPA. Clean engines help provide optimal fuel economy and performance, and reduced emissions. Those vehicles that have experienced deposit related problems would especially benefit from use of Top Tier Detergent Gasoline.

The Top Tier program, begun on May 3, 2004, is a voluntary program initiated by the four automotive companies. Some fuel marketers have already joined, although not all fuel marketers will offer Top Tier Detergent Gasoline. Once fuel marketers make public announcements, a list of all fuel marketers meeting Top Tier standards will be made available. For now, it will be necessary to look for the “Top Tier” designation at the gas pump.