Why 91?
Why 91?
Just wondering why they have 91 octane since no car (that I know of) requires it.I've only seen requirments of 87 or 93.NowI understand I Cali that they don't have 93 or something like that,but wouldn't that be hurting all those cars that require 93 and simply cannot accept 91.Also,if a car is made for 87 oct (ex. 98 corolla),would it do any good to choose 91 over 87 (now I think I read somewhere else in this forum that 93 in such a car would actually hurt it so I'm not asking about that)?
1990 Corolla SR5 5-speed,wish it was a GTS
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There's no point putting 91 or 93 in your car as youe engine has too low a compression ratio to benefit from anything better than 87. I don't remember why they have both 91 and 93 at some places, but I do know that some cars recommend 91 (such as my Maxima) while some require 93. I still put in 93 when I find 91, since people on maxima.org claim to get better gas mileage with the 93 for just 5 cents more per gallon, plus I'm not a granny behind the wheel
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I always thought most cars were tuned for 91 octane, since that's all we have here in CA... Then again, there's a few car models which are "california-only", meaning that the other 49 states get one car, and californians get one with some tweaks for emissions purposes, etc. Some CA-only cars also mkae less power.
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Scarface, the octane number is only a measure of how much you can compress the stuff before it spontaniously ignites. Putting higher octane gasoline in a car that doesn't require it wouldn't do you any good unless you had reason to belive the compression ratio of your engine had gotten higher. It shouldn't make any difference in gas mileage or anything, in theory. It might, for all I know, because all I've learned is theory, but it shouldn't.
LS1Leader: 91 is all we have in Cali? I just filled up with 87 yesterday...
LS1Leader: 91 is all we have in Cali? I just filled up with 87 yesterday...
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As in, 91 is the highest that's regularly available at most pumps.Tiamat wrote:LS1Leader: 91 is all we have in Cali? I just filled up with 87 yesterday...
EDIT: Now that I re-read my first post, I was being an idiot and wasn't very clear. I meant that for cars that were marked as needing premium fuel, that I expected those cars to be tuned to 91 octane vs. 93 octane.