Recently AAA did a study of gasoline and concluded that in the long run, it is less expensive to buy TOP TIER™ gasoline than nonrated fuel especially since the price differential is only about three cents. First of all, what is TOP TIER™ gasoline? In 1995 the EPA developed a standard for detergent additives and cleaners that must be in all gasoline, but as engines advanced, automakers saw the need for a better additive package. In 2004 six automakers (General Motors (GM), BMW, Toyota, Honda, Volkswagen, and Audi) got together to create a new standard requiring significantly higher levels of cleaners, because the existing standard did not ensure optimal engine performance. If a retailer is selling TOP TIER™ gasoline, the enhanced additive package will be in all of the grades (octane levels). AAA found in the study that non-TOP TIER™ gasoline caused 19 times as many carbon deposits as TOP TIER™ gasoline. These carbon deposits will reduce fuel economy, increase emissions and degrade vehicle performance, especially on newer vehicles.
To illustrate the consequences of using gasoline with low or no detergents, I’ll have to date myself. In the mid-’70s, I was working for a Saab specialist. It was right after the ‘73 Arab oil embargo and the gas companies were trying to keep prices down, which they did by eliminating the additives. Saab 99s had electronic fuel injection through 1974. One of the most common problems we experienced was the injected 99s missing, jerking and generally being low on power. At first we tried to compensate by enriching the fuel mixture by computer and sensor adjustments, but in the end, it turned out to be clogged fuel injectors that were the cause. We cleaned them with spray carburetor cleaner and a toothbrush.
Finally, GM (who also used fuel injection on some models) warned the gasoline companies that if they didn’t put the detergent additives back in the fuel, GM would tell all their customers to use only Chevron gasoline. At the time, Chevron was one of the only companies using the additives. The gasoline companies heeded GM’s warning and in a matter of four to six months, the clogged injector problem was gone.
Octane level is not the same as the additive package. Octane determines the temperature/pressure at which the fuel will ignite. For example, 85 octane gasoline ignites at a lower temperature than 91 octane. Usually higher compression engines need higher octane to prevent premature ignition that can damage engine components. Be sure to use the octane recommended in your owner manual. Also remember, if you use a higher-than-recommended octane the only difference will be a higher charge on your credit card.
Considering the small cost differential between TOP TIER™ and non, I fully agree with AAA that TOP TIER™ should always be purchased. To illustrate the point, engine decarbonization runs around $125 or better. At three cents per gallon, it would take 4167 gallons to pay for it.
For a list of TOP TIER™ brands and retailers click here: https://www.toptiergas.com/licensed-brands
