Octane ratings

sublimemike · Post by **sublimemike** » Tue Sep 01, 15 3:23 pm

What would be our equivalent to US 100 Octane? I know their fuel is rated different to ours.

RobTwin · Post by **RobTwin** » Tue Sep 01, 15 4:17 pm

Not sure of the exact figures but I read somewhere that you add 5-6 points to the US number to get the UK/EU equivalent...

latil · Post by **latil** » Tue Sep 01, 15 5:44 pm

https://en.wikipedia.org/wiki/Octane_rating Yes 5 points is about right.

John · Post by **John** » Tue Sep 01, 15 6:25 pm

So 100 in the states would equate to 105 over here then?

sublimemike · Post by **sublimemike** » Tue Sep 01, 15 9:31 pm

Seems so John. I've seen something in the states but it needs 100 Octane minimum. It's not going to happen unless the motor gets pulled to pieces , pistons etc 12.5- 1 compression - just too mad, I thought it was going to be. Race fuel only it sounds like.

John · Post by **John** » Tue Sep 01, 15 9:57 pm

Yeah sounds a bit much. You could try retarding the timing but all a bit of a gamble

sublimemike · Post by **sublimemike** » Tue Sep 01, 15 10:10 pm

Yes John , 454 Chebby , Ally heads, the timing is around normal 18 intial 38 max, possible scope to decrease.....