As the owner of an auto shop, I am frequently asked what the best fuel for a given car is.
Unfortunately, the answer isn’t quite that simple. But understanding the different components of gasoline fuels can help you make an educated decision about what to put in your tank.
Historically, gasoline was a mix of hydrocarbons (an organic compound of hydrogen and carbon atoms) distilled directly from crude oil. In the recent decades, it has become a sort of cocktail mix of chemicals, including traditional gasoline, ethanol, stabilizers, detergents and anti-corrosive agents. This occurred over time to improve engine performance, to reduce emissions and to create a more economical fuel.
Ethanol, or Ethylene-Alcohol, is a sort of filler additive that creates cleaner emissions, but often with a lower fuel economy.
Stabilizers extend the shelf life of gasoline. As a naturally unstable chemical, gasoline will decompose over time and, if left in a vehicle too long, becoming a varnish-like substance that can clog filters, fuel lines and injectors.
Detergents in gasoline mixtures work to reduce the carbon build-up around the injector, intake valves and in the combustion chamber.
Anti-corrosive agents prevent the gasoline from damaging fuel delivery system components like the pump, valves, seals and hoses.
These components are mixed at different levels to create winter and summer blends. The winter blend is designed to alleviate engine stress caused by cold starts and cold weather driving, but can result in 10-20 percent reduction in mileage during the coldest months.
The way the components burn in the engine gives gasoline its octane rating — a ranking of the gasoline’s ability to help reduce engine knock, engine noise caused when an incorrect ignition allows air and fuel pockets to ignite outside the typical combustion front. A higher octane rating increases the amount of compression the fuel can take before igniting incorrectly.
Where you purchase your fuel and what grade you choose can make a significant impact on the cleanliness of your engine.
Federal fuel standards require only a minimal amount of detergent in gasoline. Many automobile manufacturers have agreed on a higher standard to maintain clean engines, which has led to the advent of top tier fuels sold by petroleum companies to meet these higher standards.
Top tier fuels have more detergents to keep the injector, intake valves and combustion chamber clean of fuel build up, which can hinder fuel efficiency and even engine operations.
The best fuel choice will always be what is suggested by the manufacturer. Many cars, especially European cars, require top tier fuels that are high in octane.
If the manufacturer does not have a specific recommendation for fuel, finding the right choice becomes a bit of a science experiment.
Some vehicles run just fine on the average quality fuel found at the corner station or grocery store. Others are highly sensitive to the lack of detergents or high alcohol content from ethanol.
But one thing to keep in mind, wherever you purchase your gas, is that lower prices often mean lower quality. Though you may be saving money today, lower fuel efficiency will require you to fill up again sooner, and low quality gas may also cause your engine build up more grime, which means more frequent cleaning and maintenance.
Ken Clark is the owner of Sparks Car Care, Federal Way. He can be reached at 253-874-1070, www.facebook.com/sparkscc or sparkscc@comcast.net
