What octane fuel do you guys run with a 12A? I've heard running 87 is better for a rotary because it burns slower and utilizes the trailing plug effectively. Any info???

 

Surprisingly enough, the truth is that the higher the octane, the slower the fuel burns. Worked at a Shell garage for several years and could never convince some customers, usually older ones, that high octane fuel was actually bad for their 87 octance engines.....Once again, Read the Manual!

For Sevens the lower octane is fine. Though our cars might not get the high mileages of the boingers out there, at least we can happily dump in the lower octane fuel. One thing though, ususally the lower the octane, the less additives. So "Jerrie's Groovy Gas and Go" may not really what you want to put into your tank. I don't particularly like putting alcohol/methanol into my cars as you know what alcohol/methanol does to rubber hoses? Dissolves 'em. Where does does that stuff go? Into your fuel filter if you're lucky....On into your injectors/carb jets and engine if you're not....I used to use nothing but Marathon or Shell, as they were straight gas, but recently I note that our local Marathons are now putting alchohol/methanol into their fuel, so I guess I'm left with only Shell around here.

Denny, from the 'ol corncrib...

 

So, how do you tell who has methanol/alcohol? Are they required to label the pumps? What about oxygenated gasoline? (Used in the winter around here.)

 

Hiya, Pele...

Nice hearing from yuh. Yeah, around here stations are required to post a message on their pumps advising that their fuel contains 10% Alchohol/methanol. I KNOW that Shell doesn't use it...Thanx for the comment on my other post regarding what to look for...

Denny, from that 'ol corncrib

 

Same goes in michigan. They are required to state the maximum percentage of alky/ethanol in the fuel

 

What about products like HEET and ISO-HEET? Fopr that matter, what about pouring isopropyl alcohol in the tank? Or even denatured?

 

I'm lucky that we don't tend to have alcohol/methanol up here Canada.

The only reason to go higher than 87octane on a RX-7 is you have a forced induction (turbo or SC) system installed.

If you want a good quality fuel additive, try Lucas Fuel Treatment. Cleans the injectors, lubes the seals, and reduces carbon deposits.

 

With my 13b i use usually atleast 91 octane... At the beginning i used 87 but once when i tried somthing higher the car ran smoother so i stuck with it... Also it seems slighty faster

 

I work at an Esso station (Exxon to you), so I know a bit about fuel. First off, where do you buy your gas? Some brands are a bit better than others. Especially in the US.

Octance does NOT enhance the performance of your car. Octane simply prevents detonation. That's it.
That said, higher frade fuel often has other additives in it which my be what's helping your car.

Try this:
Pick up a bottle of a high quality fuel additive (I use Lucas Fuel Treatment). Next time you're near empty, fill half a tank of 87 Octane, add the fuel treatment, then the rest of the gas.

See if this helps. If not, it leaves two possibilities.
1) You're using a crappy brand of fuel.
2) There is somthing wrong with your car.

Hope this is helpful,
-Spencer