To fuel or not to fuel, that is the question.

    Have been running high grade unleaded ever since I've had the Slingshot. Decided to fill up this morning with mid grade. Can't tell any difference in performance even though Polaris recommends high grade. What fuel does everybody else use?

    If you look at the service manuals for other vehicles that run this engine, you'll see that not all of the manuals specify high test required.


    Personally, I alternate between the mid-grade and high grade, depending.


    Anyone ever run anything above 93? Say, 100 octane?

    I usually run regular unleaded with no knock apparent to me., But i drive it fairly conservatively with the occasional rabbit start off the stop light, LOL :00000019:
    And even on the Interstate usually keep it under 80.
    But mine is bone stock.
    Don't even have a CAI on it.

    Ran regularly when I had no supercharger and in stock form.... no issues or knocking - of course I run 93 up now.





    WE WERE ALL HUMANS UNTIL
    RACE DISCONNECTED US,
    RELIGION SEPERATED US,
    POLITICS DIVIDED US,
    AND WEALTH CLASSIFIED US.

    Quote from Bill Martin

    @KayTwo on the 100 grade octane I'll answer I'll repeat what @rabtech told me - won't be able to tell any difference for $7 a gallon - that was nuff for me

    That works.


    Once a year or so I burn a few gallons of the 100 ethanol or 110 non-ethanol in my truck just to clean things out. Of course, I also use Lucas and Star-tron fairly religiously the rest of the time, so the high octane stuff probably isn't much more than a placebo.

    I don't know about the slingshot since i don't yet have one(grrrr) but for all my other vehicles and bikes i will always use premium(heck even my riding mower/snowblower use it) it has never been about performance but about the fact that it will keep the injectors cleaner while also providing a better MPG( if that is even a thing on a sport car/suv), I am also quite adamant about certain brands of gasoline being better than others(Mobil,Costco,BP) = good. SuperAmerica,Freedom,random Mom&Pops = bad


    For example i have tracked the miles of almost all our vehicles using Fuelly - Track and Compare your MPG and based on the data Superamerica has the worst possible gas in the state of MN(consitently 2-3 MPG less than costco which is my preferred brand due to convenicence).


    For my boat there is a 3-5MPG difference between getting gas a the local river station vs bringing my own from costco.


    I am also one of those that firmly believes that not all brands of fluids are created equal and that synthetics needs to go on EVERY darn possible thing(Mobil Fluids on everything).


    also given the fact that prices are so close between "cheap gas and premium gas" it is just irresponsible not to go for the good stuff, in my opinion is cheap insurance, kind of like waxing your car/s during winter to protect the finish from salt damage here in the northern states.

    Is not that I am mean, I just don't sugarcoat what I say.

    Quote from DeputyDawg

    Have been running high grade unleaded ever since I've had the Slingshot. Decided to fill up this morning with mid grade. Can't tell any difference in performance even though Polaris recommends high grade. What fuel does everybody else use?

    The computer will train/adjust itself to whatever grade of fuel you are running, for better or worse. More than likely you will not see an instant change

    Quote from KayTwo

    oh, don't get me wrong, there are guys on the Forum who will tell you to only run the high grade stuff, especially if you are running a turbo. I just read what's out there.

    To each his own. Less performance, less efficiency, and less gas mileage. I never run anything but 93 octane, non ethanol as long as I am close to home. Even the lawn gets the good stuff. When I am out of town it is the highest octane at the pump, a few times I have stopped a stations that the highest they had was 89 so I just drive off to the next station.

    Quote from KayTwo

    That works.
    Once a year or so I burn a few gallons of the 100 ethanol or 110 non-ethanol in my truck just to clean things out. Of course, I also use Lucan and Star-tron fairly religiously the rest of the time, so the high octane stuff probably isn't much more than a placebo.

    And the burned fuel smells completely different from regular 93 octane fuel.

    Just think of a stock slingshot as a stock Pontiac Solstice or a Chevy Malibu. Its no different. Same exact drivetrain. If you want to run regular unleaded go right ahead. If you want to run super unleaded then that is fine also.. Can you tell a difference? Probably not. It may help in fuel milage but I believe any differences will be ironed out by the ECU.


    Once you add boost to any of these engines you can ONLY run super unleaded. This isn't a suggestion. It is a absolute MUST DO. 92 to 93 octane is a minimum when running boost.

    And VP racing fuel does smell really good. :-)


    Also one more note about fuel. You CAN NOT run e85 in our Slingshots. I know the engine is an LE9 and not an LE5. And I know the difference is its ability to run e-85. But that is just the engine they picked. The other goodies required to run e-85 are not on the slingshot.

    If you are boosted and you have to put a few gallons in of regular unleaded don't panic. Just keep your foot out of the gas pedal till you fill up with super unleaded a couple of times. I say a couple of times because depending on how much regular you have left it will dilute down the first time you fill up.


    That way you won't pop the engine by detonating it. Octane is boosts friend.