What would be the advantage to burning higher octane gasoline than your engine was tuned for?
Lexus recommends 92 octane for the IS. Wouldn't filling up with 94, or even 100+ (which I've never seen in L.A.), just be a waste of money?
I have heard that some 76 stations in Los Angels area sell fuel close to 100 octane out of the pump, but I have asked around and I did not find any that does.
Running higher octane fuel than recommended with the stock injectors may damage the engine, because the engine will run hotter (correct me if I am wrong). So, you really don’t want to over do it unless the engine is designed to run with high octane fuel. If I really want to do this, I will probably mix half tank of 92 oct with half tank VP red, or just add a bottle of Octane booster before fill up.
One of the 76 stations here in Yorba Linda actually had 108 for a while. I don't know why you need it because higher octane is just to prevent knocking, so for a car that runs fine without retarding the timing using 92 octane, you shouldn't be able to gain anything. The skyline probably had extremely high boost plus high compression ratio, and cannot run on anything less 118 without detonation. Maybe the car need to run JetA?
I was in Europe this past summer, I spent most of my time in Germany where I did most the driving. Anyway, the first time I pulled up to the gas station I didn't know which gas to pump. Their lowest octane was 94 and peaked out at 98. Why the necessity for such high octane? Or is it that it's measured differently? Anyone know the answer to this?
At the time I was driving a MB new C-class, so gave it some 98 octane, it ran fine. The next time I pumped it with 94, it ran fine as well.
And while I'm at it. To all of you who are or have complained about gas prices. Take this into consideration: A liter of gas DM 2.50, that's $1.25 for a liter. There's approximately 4 liters in a gallon, so do the math. Yup, almost $5.00 a gallon. I have no problem of paying $1.57 a gallon here in NJ, and will do so with no complaints at all.
Martin M: I was in Germany in September and it was already more than $4.00 a gallon. We don't really know how fortunate we are over here. (We had it a little easier driving a diesel Audi A6 wagon. There seems to be a bigger differential in diesel prices over there, so we were getting about 33 miles per gallon on the diesel...lucky us.)
In the Seattle area, looks like the super fuel is mostly 92 octane.
I remember a few years ago seeing a Sunoco station which had this gas the called GT or something like that 104 octane for 3 bucks a gallon 5 years ago. I went back to the same sunoco and they stop carrying that gas due to lack of demand..... DAMNNNNNNNNN all you penny pinching enviormentalist, Most your ruin everything in this world!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Octane in Europe is measured differently. Can't remember the particulars, but it works something like this:
Octane numbers in the US based on an average of two different octane numbers.
Octane in numbers in Europe are based on the highest number.
Sorry I can't remember the particulars on the different numbers.
Also, running a higher octane rating won't help your car. If your car runs good on 92 it won't run better on 98. I think that octane is a rating of how much heat it takes to burn. The higher the number, the more heat required. That is why you would want to lower the compression in a high boost car. If your car's compression is to high it could create to much heat and detonate without spark. Not a good thing.
I actually saw this in a Jet Ski I re-built. Couldn't turn it off and pulled the spark plug wires and the thing kept running on it's own. Had to get a plug puller out to stop it before it blew the motor up! Wasn't fun at the time! lol
The only reason to run a higher octane fuel is to avoid pre-detonation. This can be caused by higher compression, forced induction or hot spots on the piston or cylinder caused by friction or carbon buildup. Octane raises the flash point of the air fuel mixture and allows the spark to do it's job rather than having some hot spot in the combustion chamber do it first. A disadvantage of octane is that along with lowering the flash point, it also slows down the rate at which the fuel combusts - yes that means that you can (lots of chemical equations, physics and geometry to determine how it affects individual motors) ge worse performance out of a high octane fuel than a lower one.
Not a very scientific experiment, but my NA track car dynoed lower on UNOCAL 104 than it did on UNOCAL 93 - conversly a friends supercharged track car dynoed much better (after dialing in the advance) with the higher octane fuel - same engine (except for the blower and extra fuel pump).