What's the difference between regular, plus, and supreme gas?

Some people put plus because they want to be nicer to their car. Some other people told me only a specific type of car needs plus or supreme-otherwise it don't make no difference. If that's true, how do I know what this car needs? It's a Toyota Avalon--is that what distinguishes them?

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  • 1 decade ago
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    Higher octane fuels have a higher resistance to something called pre-ignition. Basically making it harder for the fuel to combust until it is ignited by the spark plug.

    The only cars that need the high octane fuels are those with an engine that have high compression. (In the past these were mostly sports cars, however many manufacturers are placing high compression engines in other cars too). Some cars with high compression engines include the Honda Odyssey and Nissan Maxima. These vehicles also have something called a knock sensor to retard spark and minimize the chances of pre-ignition by starting the igntion process at a point that is less than optimal to prevent pre-ignition. Technically this allows vehicle manufacturers to advertise a higher fuel economy rate and bring up a company's fuel economy numbers by testing with the higher octane fuels.

    Your owner's manual will inform you exactly which type of fuel you'll need for your car. Using fuel of a higher octane, typically will not hurt your vehicles engine, while using a fuel of a lower octane will cause what is known as "Engine Knock". An engine that has high compression, will actually have places inside the cylinder that is hot enough to begin the ignition process that is at a point other than the spark plug. These points of pre-ignition are typically where the piston and cylinder walls meet. This will cause a flame front to start at a point other than the spark plug. If the flame front when the spark plug starts will eventually collide with the flame front generated by the pre-ignition. When these flame fronts collide, you'll get the shock waves. (and you'll hear these shock waves in the forms of "Knocking")

    If your owners manual says "Premium Fuel Required", it means no knock sensor has been added, and you must use the higher octane fuels to prevent engine knock. If you're owners manual says "Premium/Plus Fuel Recommended", it typically means you've got that knock sensor that will basically tell the electronics to retard spark and minimize/prevent knock by igniting the fuel at a point that is less than optimal, but preventing engine knock/damage.

    If it says 87 octane, then using any of the higher octane fuels won't hurt the car, but typically you won't benefit in any way either.

  • 3 years ago

    Plus Gas

  • Anonymous
    1 decade ago

    Regular, Plus, and Supreme Gas have different levels of octane.

    Octane is a substance put into gasoline that boost engine performance, so you might get a little more horsepower, cleaner fuel burn, slightly better gas mileage, and perhaps a little more life out of the engine.

    Most cars will run fine on ordinary gasoline, but sometimes people have sportcars or other high-performance engines that would need more octane. Your owner's manual will typically tell you what type of gasoline is best. I have a Toyota and run it on ordinary gasoline and it does just fine.

    Generally, this is how octane is sold by gas retailers:

    Regular - 87 percent octane

    Plus - 89 percent octane

    Supreme - 91 percent octane or higher.

    Hope this helps. Good luck!

  • Anonymous
    4 years ago

    This Site Might Help You.

    RE:

    What's the difference between regular, plus, and supreme gas?

    Some people put plus because they want to be nicer to their car. Some other people told me only a specific type of car needs plus or supreme-otherwise it don't make no difference. If that's true, how do I know what this car needs? It's a Toyota Avalon--is that what distinguishes them?

    Source(s): 39 difference regular supreme gas: https://shortly.im/1GIS8
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  • C7S
    Lv 7
    1 decade ago

    The plus and supreme is better quality. It does not hurt the car or help the car using any other gas. The higher the quality, the more power you engine gets. 92-96 octane supreme adds an average of 3 horse power to your car while you are using the gas. It does not make the car live any longer. Luxury and sports cars say they require it, but it is not true. They just want the most performance out of their vehicles to that the customers keep buying them.

    The cars Octane recommendation is either on the gas cap or inside the gas door. If it does not say anything, then that means use regular.

  • 1 decade ago

    Check your owner's manual. It should list an octane level that your car will perform best at. The difference between the types of gas is the octane level. The only way I can explain it quickly is to say that one is "more refined" than the other, kind of cleaner.

  • koma
    Lv 6
    1 decade ago

    octane level is the difference 87 reg, 89, plus, 93+ supreme, just put what the mfg. recommends for your vehicle. if you use more its just a waste of money

  • 1 decade ago

    Octane. 87reg , 89 plus , 91 supreme.

  • 1 decade ago

    look in the owners manual it will tell in it what that car needs to run on typically it should run really good on regular,but look in the manual it tells in it,the difference in the fuels is the octane rating,that's all,and the additives,good luck on it.

    Source(s): been a certified mechanic for 37 yrs.
  • 1 decade ago

    look in the owners manual it should tell you what octane gasoline to use. most newer cars are designed to run on 87 octane

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