Join Date: Sep 1999
Location: CT, USA
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Re: 93 octane in stock engine
<blockquote><font size=1>In reply to:</font><hr>
.....the hot weather my Corsica ran like crap on regular and ran better on premium..... If you tow ........hill climb....dune..or operate a POS 88 Corsica 4cyl auto with the air on in hilly Penna rural/suburban traffic on 90 degree days ......you'll reap benefits in "drivability".......albeit at a price.
The hotter the engine's running, the more likely you'll experience detonation, even if the compression ratio is such that it's normally not a problem. Then the inefficiently-running tends to run even hotter, etc..... Lugging the engine (low speed, A/C, uphill) also hurts (think about it-- open throttle, more air/fuel into the slowly turning engine increases the cylinder pressure). But the statement (again, only for non computer engines) is still true-- "if it's not detonating, you don't need higher octane fuel."
My wife used to have a '69 Bonneville convertible with a 428 (I bought it for her birthday[img]/wwwthreads_images/icons/smile.gif[/img]). In cold weather it ran OK on premium fuel, but in the summer you needed Sunoco Ultra (96 octane-- no longer available, I think) and a can of octane booster to keep the engine from practically leaping out of the hood.
There is always a law against doing anything interesting.