As gas prices continue to rise, more and more motorists are abandoning customer loyalty to well-known and trusted providers, such as Shell and Exxon, to save money. Others believe the tradeoff for cheaper gas is lower quality, which will harm their vehicles in the long run.
Perkins Street Auto Zone manager Michael Green said there is not much difference in gas except the brand name.
“Exxon is the primary refinery [from which other gas companies get their fuel],” he said. “Other companies add additives and detergents to it.”
Daniel Martin, an extension service engineering science associate, said typically it is the additives and detergents companies add to their product that separate a Chevron and a Racetrac.
“Most companies that add detergents to their gas usually advertise it, like Chevron,” he said.
Martin has published articles in the LSU Ag Center’s Newsletter offering automotive advice. He also has appeared on a local television station to give automotive maintenance tips.
Green, a 1996 LSU graduate, said the same is true for different octane levels of gas. He said unless it is a high performance car that requires a higher-octane level gasoline — premium gas versus regular — motorists can get satisfactory performance from regular grade gas.
Martin agreed there is nothing wrong with regular grade gasoline.
“As a consumer, you have to ask yourself, is it worth 20 cents a gallon more [to buy premium gas]?” Martin said. “Unless your valves knock on you, there’s no reason not to use 87 octane [regular] gas.”
Martin said the higher performance cars, however, have a higher compression ratio than other cars; therefore, they require a higher-octane gas because they burn slower.
“They need that higher octane to have a controlled burn,” he said.
He said when the valves begin to knock or “ping,” the gas is burning too quickly. In this case, a higher-octane gas would be helpful. Motorists should check their owner’s manual to see which gasoline grade the manufacturer recommends.
“You have to feed your car what it needs,” he said.
Another advantage to using a higher-octane gas might be better fuel efficiency because it burns more slowly than low-octane gas, Martin said. However, motorists must weigh the pros and cons.
Erin Riley, a mass communication senior, said she used to use premium gas in her car.
“I thought it was better,” she said.
It was not until her uncle advised her that regular-grade gas was sufficient for her car that she stopped using premium gas.
Martin said he puts Chevron’s gas in his car because of the detergents they add to the fuel to help keep the engine clean.
Green has six vehicles and uses premium gas in his 1970 Corvette and his Honda Prelude but puts regular gas in the others.
“As long as the vehicle doesn’t run into destructive qualities in gas, like water, it will be fine,” he said.
Gasoline Tips:Most cars run best on regular grade gasoline (octane level of 87).You may need a higher octane if your engine knocks (makes a pinging sound).For the correct octane level, check your owner’s manual.