MBFLO

As i was fillin up lastnight i seen a pump with 100 octane gasoline .. I was curious if i was to pump that into my e55 would it have negative or ill effects on the car . i was just curious as what it would do to my car running on stock ecu and such ..

JamE55

It will not have any negative or ill effects other than your wallet. If you're running a stock ECU it won't do much. Only way of taking advantage of a higher Octane is if you're ECU is tuned to read it. Otherwise you're wasting your $$$.

MBFLO

Ok thanks for the info ! Yea figured without a tune not much can be done . At almost 6 dollars a gallon one would think it would improve performance .

JamE55

That's actually a little cheaper. Over where i am it's about $8 bucks a gal. As far as HP increase IIRC i've gained about 15-17hp.

AMS Performance

It does help alittle bit, stock ECU can adapt up to roughly 95-96 octane but its not really going to do much past that. It will allow the ECU to roll on full timing instead of pulling timing for whatever reason, which is why the car will run smoother with high octane fuel versus standard octane. Don't expect lots of power though...

ABALONE

I remember when i was on a German roadtrip down to the AMG factory down through the Autobahn two years ago. As soon as i got into Germany and started to fill my car with their fresh 100 octane fuel i felt the car gained around 15-20 hp and lots of torque Back then the car had only a ECU done. It was a really WOW experience

MBFLO

shoot now im temped to go throw it in just to see if it gets some hiccups out lol

Chappy

There's a station near me that sells 100 octane at the pump. It may turn your exhaust tips slightly blue - tried this several years back before going to the drags.

Also, there is a significant difference in calculating octane RON vs. MON. That euro 100 isn't the same as 100 in the U.S.

Try it _ and have fun!

saintz

Is the 100 octane you found unleaded?

You can also use toluene or xylene/xylol to boost octane in regular gasoline. You can find it at Lowes, Home Depot, or speciality paint stores like Sherwin Williams. This might be a little cheaper and easier because one gallon will "spike" a half tank of gas for a lot cheaper than buying the equivalent amount of high test pump.

AMS Performance

Euro 100 octane = US 95 octane (roughly). (98 = 93 and etc).

It does help more on FI cars than NA cars for obvious reasons.

Chappy

Absolutely. Factory cats are expensive.

karl.w

im running on 108 octane Liquefied petroleum gas (LPG) and have been for 2 years now and 35,000 miles

Now im going to get the ecu chipped to see how much power i can get by advancing the timming by as much as the 108 ron fuel will let me

ejsheltra

We used to run the 105 Aviation gas from the airport in Massachusetts in our 70 Boss 302 race car. That was in SCCA GT1 class B production. After a teardown the valves were clean with no carbon build up and the headers were clear of any carbon soot. That stuff was potent. We added Top oil cylinder lubricant since the Av gas was unleaded and the motor at the time was designed for leaded fuel. It did allow for a significant advance in spark and top end power above 5K was much improved. That motor still lives today.