Please clarify!!!
#1
#2
- Jack
#3
Shouldn't cause any problems, that's a pretty minor octane difference. Yes, you might be better off reducing the timing by 0.5 degrees, but that may not even be necessary. What's the elevation where you live? If you're at or above 4,000 ft, I wouldn't worry about reducing the timing at all.
- Jack
- Jack
#5
Just one more question then, Outlaw. How is your fuel graded? Is it the the "Research" Octane number method, or is it the average between Research and "Motor" octane numbers - the "(R + M) /2" method used throughout the States?
If you have 90 octane gas that's graded using the Research number, it's actually equivalent to 86-87 octane gas here. There's probably something on your gas pumps that will tell you about this. Another tip off that your gas is Research graded will be that your "hi-test" will likely be 95 octane.
However, if your gas is 90 (R + M)/2 octane, at your altitude and temperatures, you should be fine without adjusting timing.
- Jack
If you have 90 octane gas that's graded using the Research number, it's actually equivalent to 86-87 octane gas here. There's probably something on your gas pumps that will tell you about this. Another tip off that your gas is Research graded will be that your "hi-test" will likely be 95 octane.
However, if your gas is 90 (R + M)/2 octane, at your altitude and temperatures, you should be fine without adjusting timing.
- Jack