93 Octane Gas

Octane requirements vary depending on what compression your engine is running. Turbocharged engines (lowered compression ratio for safety) and higher compression normally aspirated engines need more octane to prevent knocking (pinging) or premature ignition (very bad for engines). Testarossa may need as high octane as possible to minimize knock. Today's high end sports cars can retard the ignition advance to adjust for lower octane gas and higher octane gas will mean higher potential performance before knocking occurs.

 

This is what higher octane gas does.



It is necessary for high performance engines to use higher octane such as 91 because the compression ratios in the engine are much higher and there is a possibility of premature detonation (meaning the gas/fuel mixture combusts BEFORE the spark plug ignites it) with lower octane gas. Higher octane gas burns slower, eliminating premature detonation.


If you want performance, you can tune the car to take advantage of higher octane gas, but unless tuned, save your money. Using 93 wouldn't hurt, but 100 octane won't do crap.

 

I run max octane in anything older than 1990.

 

I didn't design it so I can't say for sure but I got better mileage out of the car and the few techs I talked to confirmed this. Perhaps it's a myth through BMW?

 

I've heard that as well. I know that when I tuned my ex-Porsche Boxster to run exclusively on 93 octane, my MPG went up by 4. Perhaps it burns more efficiently. I'm no expert..

 

There is a station at Road America in Elkhart Lake, Wi. that has 98 and 110 octane. I took a picture of a dude filling his 911 GT3 (old model not current) with the 98. I think that the 110 was leaded and I'm guessing the 98 wasn't.

 

Right, if it was TUNED for that. He said the M5 does that from the factory. I kinda doubt that....

 

My BMW was meant to run on 91 and higher octane. By running 87 or 89 you're taking away from the performance. If you bump it back up to 91 the car will run better and have a more favorable diet.