octane usage
 

after reading about 7 pages of the cumulative gas thread, i got tired and wanted to see a poll on how many people use what gas. i've been using 93 octane but if more than 60% of you use 87 with no problems i'll try it out for myself. thanks for voting.

My car performs just fine on 87.

the car is tuned for 91

Maybe so, but from what I have read from the more rotary knowledgeable members of this forum only boosted rotary motors need premium fuel. But hey, some cars like the 87 and some don't, mine just happens to run better on it, and hopefully keep the carbon build up to a minimum as well.

I use 87 octane with the recent hikes in gas prices. Everything seems OK however, I noticed a heavy, black sooty build-up on the inside of my exhaust tips. Seems to be heavier when I use 87 as opposed to 91.

No option for me...:(
I run SHELL V-POWER 99 ocatne. :) :) :)

Unless car pings on 87 octane, use that one for more power and better efficiency. If it pings, use 89.
More important is to use a good brand. My car sees Shell 90% of the time. The rest, is BP/Amoco. Not all same octane gasolines are the same - the (R+M)/2 method used for rating it is not really descriptive of real performance (i.e., many combinations of two numbers of R and M will give you the same average).

Just bought my '05 RX-8 with 180 miles on it a week ago. I live in Colorado, and was told by the dealer, that due to the altitude, I can run 87 octane with no problems. At lower altitudes, should I travel, I should increase the octane rating, to say 89 or 91, of the gas I buy.
At this time I am haveing no issues with milage or performance.

Just curious as to what elevation has to do with which octane to use?

Only 93 for me.

heard that too...apparently if we dont have our cars boosted and tuned to run high octane that is useless and 87 is good enough on N/A. also heard that 87 would yield to better gas mileage. in the worst case situation you'd save money and it wont hurt your car or lose power.

Absolute pressures in the combustion chamber are lower as altitude goes up. Thus you don't need high octane at higher altitudes.

I run 89 here in Seattle, but sometimes I do notice more hesitation on a hard 1-2 shift than I did with 91. All other driving is the same so I don't worry about it.

where's RG when you need his input????! :sadwavey: