Fuel Tutorial

The first thing you must understand about today's fuels is that the environment is the first consideration and the engine performance comes second. The Environmental Protection Agency (EPA) plays a heavy hand in today's Gasoline and Diesel fuels development.

The Mis-Information Crisis

No, it's not a conspiracy but it sure is a mess. We have ongoing changes in air pollution standards in the United States. The Environmental Protection Agency (EPA) mandates changes in fuel chemistry to meet these cleaner air standards.

The engine manufacturers are also required to produce engines with computer controlled emission devices to further reduce air pollution. When we the consumer have a complaint about mileage, power, starting, general drivability, etc., what do we hear? It must be the gas/diesel, or it must be a problem with the computer or a sensor. If you have an engine with a carburetor, most likely when the engine was designed there was no concept of what gasoline would be like today.

When consumer complaints are related to fuel chemistry, the vehicle manufacture must collect enough data to prove to the fuel refiners and the EPA that a change in fuel chemistry is needed. Of course all this takes years. Most fuel chemistry changes must be approved by the EPA on a regional or national level. However, to bring a can or bottle of fuel additive to market is not nearly as difficult.

Who's to blame for our fuel system problems? The EPA, fuel refiners or vehicle manufactures? Well the EPA does not care about our problems and the refiners do what they are told by the EPA and the vehicle manufactures try to work with the gasoline and diesel that we end up with.

Refiners and vehicle manufactures don't make a public issue of the problems that exist with today's fuels. Admitting to problems carries a certain amount of liability. However, manufacturers' service bulletins and documents submitted to the Society of Automotive Engineers Fuels and Lubricants Committee support the statements I have made.

We have ended up with one size fits all fuels. Depending on the year, make, and model of the vehicle(s) you own, the extent to which your mileage and drivability suffers will vary. With engines and fuels becoming more sophisticated, fuel quality and engine tuning has become more critical than ever before.

More facts

Due to EPA mandates, gasoline and diesel fuels are very similar from brand to brand. Low Sulfur diesel and reformulated gasoline provides less performance than previous fuels.

Reformulated/Oxygenated Gasoline accounts for 30% of all gasoline sold in the US. The EPA is ever increasing the requirement of special design fuels.

Low Sulfur Diesel for highway use is sold in all 50 states. California low sulfur diesel is only slightly different. No fuel system is exempt from problems. Since 1991 there has been a 500% increase of additive sales.

Misinformation and deception about the fuel we buy is common. The Federal Trade Commission (F.T.C.) has sued numerous refiners concerning false advertising as to performance and additives in gasoline. High Octane is usually a waste of money. In some new design engines high octane can leave more deposits.

The phrase "Premium Diesel" means nothing: there is no "national definition". You have to ask what it is.

Watch out for those warranty loopholes. We are told to use a "good quality fuel." We are responsible for the fuel we buy.

It is cheaper to maintain your fuel system than it is to fix it. The benefits of a good multi-function fuel additive are very cost effective. Engine performance and mileage will remain consistent. Also, you will improve the longevity and reliability of fuel system components and emission control devices.


Oxygenated fuels, with methanol and/or ethanol blended into the gasoline, have lower energy and thus reduce fuel economy. Typically, there is about a 1-mpg penalty for a vehicle that gets 25 to 30 MPG on 100 percent gasoline. Using fuels of a lower octane than the vehicle was calibrated to will cause increased "Knock Sensor (KS)" system activity. This will result in a net decrease in spark advance and thus poorer fuel economy.

E-10 Unleaded (10% ethanol / 90% gasoline) is approved under the warranties of all domestic and foreign automobile manufacturers marketing vehicles in the United States. In fact, the nation’s top three automakers, Daimler-Chrysler, Ford and General Motors, recommend the use of oxygenated fuels such as ethanol blends because of their clean air benefits and performance qualities. Ethanol is a good cleaning agent. In newer vehicles it helps keep the engine clean. In older vehicles it can sometimes loosen contaminants and residues that have already been deposited in a vehicle’s fuel delivery system. Occasionally, these loosened materials collect in the fuel filter, and can then be removed simply by changing the fuel filter. All alcohols have the ability to absorb water. Condensation of water in the fuel system is absorbed and does not have the opportunity to collect and freeze. Since ethanol blends contain at least 10 percent ethanol, they are able to absorb water and eliminate the need for adding a gas-line antifreeze in winter. Ethanol is a fuel for old and new engine technology. Automotive engines older than 1969 with non-hardened valve seats may need a lead substitute added to gasoline or ethanol blends to prevent premature valve seat wear. Valve burning is decreased when ethanol blends are used because ethanol burns cooler than ordinary unleaded gasoline. Many high-performance racing engines use pure alcohol for that reason. Modern computerized vehicles of today, when operating correctly, will perform better than non-computer equipped vehicles. The ethanol in E-10 Unleaded adds two to three points of octane to gasoline—helping improve engine performance while keeping engine parts cleaner. E-10 Unleaded also helps reduce toxic exhaust emissions. Improved performance is due to the vehicle’s computerized fuel system being able to make adjustments with changes in operating conditions or fuel type. Some of the chemicals used to manufacture gasoline, such as olefins, have been identified as a cause of deposits on port fuel injectors. Today’s gasolines contain detergent additives that are designed to prevent fuel injector and valve deposits.

Fuel volatility will vary depending on geographic location (I.e., altitude) and time of year (fuel intended to be used in higher ambient conditions is formulated with less volatility). This can make cold driveability as big a problem during summer months as during the winter. There may be additional variation in the volatility characteristics of pump gasoline, caused by the differences in fuel manufacturers, blends and storage times. As EPA fuel volatility standards are lowered, variations between fuels (which may further reduce volatility) becomes a critical factor influencing cold engine performance."