91 and 95 octane
 

we can get only 91 and 95 octane fuel, nothing less. its the same price! in the future they are planning to sell only the 95 in austria. should i do a timing adjustment to go with 95 or is it fine like it is?

chris
454 mag

I have a feeling your motor won't know the difference.


Darrell.

Chris,,,in europe the fuel octane is mess. diffrent.
A 91 european octane fuel is actually about 98 US octane !!!!!

So u be more then fine actually maybe better off.
I lived in germany all my life and had race engines that needet 110 octane fuel in the us and in germany i fueled the 95 or 98 shell super and they where fine .
Thats how i know because i had done that research in late 90's.

:ernaehrung004:

wow, thats intresting. so, would you recommend me to go with 91 or 95. as i mentioned - the same price. i always thought: the more octane, the better, but lower octane also has its advantages. and maybe this summer there will be only 95 available. adjusting the ignition point could be necessary. am i wrong?

First thing is to find out how your octane measurement compares to US octane ratings.

I would go with 91 in europe !!!


But may wanna check with MARCO HANISCH in Mainz Germany . Don't have his # anymore but he knows all that stuff for shure. Thats who told me and it worked.

ok, that fine, will call him

Hanisch GmbH
Reichelsheimer Str. 10
55268 Nieder-Olm

hope this is correct

Do you know what the compression ratio is on your engines? If it is low to medium, use the 91 octane. If you have a 12.5:1 or blowers, use the high octane.

I bet you do not have high compression with a stock 454 mag. 91 octane in the US is plenty for that motor.

yes, i know that 91 is enough, but i cant get that stuff!!! what happenz when i use 95? i think there is no problem wih it, but maybe i should think about adjusting something to the much higher octane than recommend.

I agree, do this first.

Running higher octane than required won't hurt your engine, it just might lose a little power (very little). Higher octane fuel burns a bit slower, and with a low compression engine you might not get a full burn on the power stroke. Advancing the timing can help if you run into that situation, but personally I wouldn't mess with it.