Downgrading gasoline could cost motorists more

Posted April 9, 2012
Updated April 10, 2012

— With the high cost of gasoline these days, drivers are forgoing the more expensive mid-grade and premium gas options for cheaper, regular gas – even if it’s not recommended for their vehicles.

According to AAA, the national average price of regular unleaded gasoline is $3.92 per gallon, while the average cost of premium gasoline is $4.19 per gallon.

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"It hits deep in my pockets," said Tanya Powell, who commutes every day from Garner to Raleigh.

She has recently made a change from unleaded plus to regular grade gasoline to save some change.

But auto experts say that while it might save motorists money now, it will cost them in the long run.

For example, using regular gasoline to fill up a Mercedes-Benz would save an average of approximately $4 on a tank of gasoline.

But the recommended grade is minimum 91 octane for a reason, says Steven Lewis, a technician at Leith Mercedes-Benz of Raleigh.

Downgrading gasoline could cost motorists more Downgrading gasoline could cost motorists more

"It will start to rattle or knock. It will make noise and especially under acceleration or heavy loading," Lewis said. "It's not responding like it should."

Lewis said the higher-end automobiles have more powerful engines that require premium fuel for peak performance.

Drivers might be able to get by with lower octane gasoline a few times, but they will actually get fewer miles per gallon, he said. That would defeat the purpose of switching to a lower grade.

"You're only hurting your fuel economy and power output as a result of that," he said.


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  • frosty Apr 10, 2012

    The gas that comes through the pipeline may be the same (or may not, not including the base octane rating, 84.87,91,93 ect.)
    But none of the gasoline has any additives in it. They are added when the transporter is loaded. Even "unbranded" gas has additives. The kind and amount is set by the company selling the gas, Exxon, Shell,BP,Marathon,Colonial, Flint Hills and others. The unbranded gas will use a "generic" additive and maybe only in the least amount to meet standards. Exxon,Shell,BP and others use their own formulas and may use more than is required to meet the standard. I know some years age Shell added three times the amount required in their super blend.

    The type of fuel required in your vehicle should have been a consideration when you chose it.

  • dgcreech Apr 10, 2012

    The other thing to remember is this - for an average person who does two tanks of fuel per week on an average car that requires a higher grade of fuel.... when you multiply it out, it isn't that much! Approx 15 gallons multiplied by $0.30 (the difference in price from regular to premium) = $4.50.... times 2 = $9. OK so $9 extra is what you pay... would you rather pay $9/week now or replace the engine in your car later when you destroyed it while trying to be cheap? My mom had a Buick Regal with a supercharger a few years back... she tried running regular in it one day and the car couldn't even get out of it's own way. It never ran the same again and she got rid of it.

  • rationality Apr 10, 2012

    I should have referenced the quote from noted and admitted liberal Ezekiel: "Easy solution. Don't buy some useless piece that requires you to waste money buying higher grade gas. At teh same time avoid buying a gas guzzling monster that you also don't need."

    Zeke loves telling you what you need without knowing anything about you, just like a politician who thinks they know what's best for you. I'm a conservative and I don't believe anyone should tell me what I need. What you do in your bedroom, garage, basement, kitchen, etc is your business, not government's, mine, or anyone else's. I know my family's needs better than anyone.

    On another note, who profits the most per gallon of gas sold, without producing a single drop of the stuff?

  • redrubberball1 Apr 10, 2012

    "I think we'll see more cars needing the higher octane fuel as federal mpg regulations get tighter. redrubberball is almost right here - knock is when the fuel ignites BEFORE the piston has reached the top and robs the engine of power and can cause serious damage over time. Octane delays ignition in high compression engines until the plug fires."

    I actually wrote a simplified explaination. Peak combustion chamber pressure needs to occur at the very top of piston travel on the compression stroke. To achieve that, the spark plug must ignite the mixture a little bit earlier to get the "burn" underway. Higher octane slows the burn. Lower octane quickens the burn. Lower octane than necessary for your vehicle causes peak combustion chamber pressure to occur just before the top of the compression stroke and causes excessive pressure on the piston and valves even as the piston is still rising. Your gas mileage statistics will tell you which gas grade is the most effective for you.

  • redrubberball1 Apr 10, 2012

    "I know gas is expensive, but if $4 per fill-up is the difference between making ends meet and not, gas prices aren't your problem. You need to get a cheaper, more economical vehicle."

    Cutting out non essential driving would go a long way. Learning to consolidate trips would help too. Even over a long period of time, changing vehicles is seldom the answer. Most people don't keep a vehicle long enough to realize the economy in that case. As Americans, we've had it good for so long that we cannot appreciate how our lifestyle is so wasteful.

  • saturn5 Apr 10, 2012

    I know gas is expensive, but if $4 per fill-up is the difference between making ends meet and not, gas prices aren't your problem. You need to get a cheaper, more economical vehicle.

  • davidgnews Apr 10, 2012

    " Love how liberal folk tell us "what we don't need". " rationality

    Considering the context of this article, your statement is anything but rational.

  • GravyPig Apr 10, 2012

    It is better to remain silent and be thought a fool than to open one's mouth and remove all doubt.

  • davidgnews Apr 10, 2012

    Pay me now or pay me later, but at the end of the day we all pay the price.

    Sorry, but if you're having a car serviced at a Mercedes dealership, then you can afford your premium blend (esp for the paltry $4 avg difference); else, you shouldn't even be driving one.

  • victoriapbeck2 Apr 10, 2012

    I too am guilty of buying cheaper gas for my galant. But not anymore I won't. I also try to stay away from Sh and the "cheaper" stations. Shell is what I've found has done my car well, knock on wood.