Quick question about octane. I've always used 87 octane fuel in my other car, even though most recommended 91 or better. I have never had a problem with any of those cars pinging etc. I have read that due to the compression of the 22re motor in my '94 pickup, that I should use 89 octane. I've been using 87 octane and the truck seems to run ok, no pinging etc., unless I can't hear it above the valve clatter. (taking car of that this weekend, had to wait for those screws) So basically I would like to hear what you all have to say about the type of fuel you use, and experiences you've had with different types.

The Owner's Manual for my '85 (22REC) lists 87 octane... That's all I use and no pininging, even when I run the 85 octane stuff in the mountains. I think the octan recommndation was changed in later years.

That's what the PO told me, he said it always pinged on him when he ran 87 octane. Now that might have had something to do with the timing chain being stretched, and the guides gone, and timing who knows where. I guess I'll know more on my engine when I quite down these valves. My audi is a 10.5:1 C/R and the BMW is a 9.0:1, no problems with 87 octane on either of those that I know of. I know that an octane rating is measure of how easily a fuel ignites when compressed, so it would seem that C/R would be directly related to octane requirements. There must be something else going on, the Audi must change something about the way it runs when it has 87 octane gas, or it would ping like crazy! Anymore thoughts?

If I run 87 octane in my '85 22R, it pings horribly, especially if the gas is a generic brand. I usually run 91 octane to curb the pinging, but with gas prices going up, I may drop down to 89.