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Thread: Cars recommending premium fuel

  1. #1

    Cars recommending premium fuel

    With the high prices of gas lately do you believe you truly should

    use premium fuel on a car that recommends it or is it a waste of

    money and it runs fine on regular?

  2. #2
    Registered User
    Join Date
    Dec 2005
    Southeast, USA
    If you ask 10 people, you will get 9 different answers.

    I did my research on this and everything points to the fact that a modern car with computer controlled ignition and fuel injection (rather than a carb) can adjust and run on Regular Unleaded gas with NO PROBLEMS. Do a Google search and research this for yourself. There are many articles from certified automotive engineers that said gas quality varies so much around the world that they have to make the cars (actually the ignition/FI) adapt and run on any grade. Of course, you won't met the quoted high performance numbers (zero to 60, HP, torque, etc) from a BMW or Merc, Audi, C6, or whatever, if you run on regular. So if THAT is important, then use the Hi Test grade.

    If you're getting screwed by the man like most working people these days and don't get cost of living raises any more, medical costs going up, retirement plan cancelled, then use your head on this subject and don't believe Big Oil lies that you will get better gas mileage (you won't). You WILL get better performance if your car is recommended to use Premium gas, but not better mileage. That is a false promise. They make a lot MORE profit on Premium than Regular (it doesn't cost 20cents/gal more to make Premium). Caveat emptor.

  3. #3
    I am me, too!
    Join Date
    Mar 2004
    If only I knew...
    In the 90' my Accord did have better mileage on premium but that wasn't that much. It wasn't worth it. Now with all the computer controls, I don't think it would make a big difference, as DirtyOWL is saying.

  4. #4
    Usually its mostly high end luxury and sports cars that ask for premium fuel

    if you can afford the car you should afford the extra gas charge.

  5. #5
    Registered User
    Join Date
    Jul 2003

    Long winded, but may be of some help

    I agree with DirtyOWL to point, your car will run on regular, but not as well. As a long term way to save a few bucks at the pump, I respectfully disagree.

    Higher octane is required for higher performing engines. Part of that higher performance is a higher compression ratio. The compression ratio is the amount of "squeeze" created when the piston moves up in the engine, just before the spark ignites the fuel/air mixture. When you compress air, it heats up. The more you compress it, the hotter it gets. The octane controls the rate at which the fuel will burn. Too little octane = too fast a burn. Too fast a burn will result in "pinging", which is actually a mini explosion inside the engine. This will quickly result in engine damage, up to, and including, blowing holes in your piston.

    The computer will compensate (partially), by retarding (delaying) the spark timing, in an effort to stop the pinging. What this does, this is where I disagree with DirtyOWL, is cause engine deposits, or what some people call "carbonizing". A carbonized engine will end up costing you more in the long run. Your engine is designed to operate within certain perameters with regards to heat, fuel ratio, etc, etc, etc, in order to stay relatvely clean internally, and operate reliably. When you start to get a build up of carbon, you can:
    End up with partially blocked intake and exhaust valves. That means your engine won't be able to "breathe". Your car will run too hot, be hard to start, and require a heavier foot on the gas pedal to get moving.
    Possibly (it's rare, but I've seen it) get a partially clogged injector. That will cause all kinds of problems, including leaking. More gas wasted.
    Potentially set off your "Check Engine" light if you foul one the dozens of sensors that newer cars are equipped with. Then you or your mechanic has the joy of finding out exactly which one.

    I feel for you, and everybody else who has to fill up with premium. My summer toy needs it, and runs like a bag of shit without it. For an every day car, you might want to try, at your own discretion, using mid grade at every second fill up. I haven't tried it, but I do know a couple of guys who swear by the practice.
    Shorter of breath...One day closer to death. Pink Floyd

  6. #6
    Pimpin' ain't easy...
    Join Date
    Dec 2005
    When i was working at an Acura garage in parts dept we had lots of phone calls of customers complaining that their TSX was not working properly and that the engine was jerking, first question was allways "Did you put regular gas in it ?" the answer was allways YES. People never read the owner manual, so we recommended either purge the system (too costly) or live with it for the rest of the week, and next time you go to the gas station put super in it.

    For myself i tried super for 3-4 weeks, and did not notice any difference from regular gas, i have a 1995 Corsica V6
    You know "that look" women get when they want sex? Me neither. - Steve Martin

  7. #7
    Registered User
    Join Date
    Nov 2003
    Over the long run if it is recommended that your car run on higher octane fuel and you always put in regular, in the short run you will gel less fuel efficiency or more liters per 100 km. In the long run, your engine will most likely start knocking. Saw many time while I was selling cars...

    They will forget what you said,
    they will forget what you did,
    but they will never forget the way you made them feel.

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