ludeowner

Hi everybody,

I'm getting close to trading my car for an RX7, but I was worried about the octane of gas I'll be putting in it. All that is available in my local area is 91 octane. Will that "hurt" the engine too much? or should I try to find a place closeby that has 92 or 93?

BTW I live in Northern California (Fairfield/Vacaville area) and I haven't seen anyplaces selling 93 octane for a while. The highest I've seen is 91, and that's the premium stuff.

TIA

RX7Elmo

91 octane is fine. that's what all we "premium" users use in california. It used to be 92 octane a few years ago.

Danny

mightyslash

91 octane is good for stock FDs. Of course a little higher is better but there's no way in hell you'd get 92 or 93 in CA. There's 100 octane race gas though, which you dont need

1FooknTiteFD

91 is perfectly fine. I have a modded FD with single turbo and I run 91 octane and it's more than safe

Kas_Rx

Damn, Australias Premium fuel is 98 octane.. Not sure about our regular.

kento1

Modded, you're OK as long as you're set up for it (i.e., watching your ignition timing). The FDs were originally designed with 93 octane minimum in mind. Stock should be fine, although I usually run 5 gal of Sunoco 104 unleaded in every tankful of gas with my slightly modded FD, and I can notice the difference in performance.

Nathan Kwok

I think in Australia they are on a different octane scale (RON) than here in the states, so it doesn't correspond.

jspecracer7

I've seen BP FD's running 1.2 kilos boost and 89 OCTANE GAS... Conservative timing and liberal amounts of fuel takes care of detonation.

FD3S_RS

With 91 octane, I think you'll lose a little bit of power.Exhaust temps will also be higher with lower octane if you drive it hard. Perhaps you can add octane booster such as NOS or 108 etc

RX7SpiritR

iTrader: (1)

I use 91 and mines drivin fine, just take care of everything else.

ludeowner

cool!

thanks for all the input guys, I just wanted to make sure that when I got the RX7 that I wouldn't blow it up the first time I go to fill up =P.

thanks again

neo_omega

in Hong Kong, they only sell 98 octane gas.

Kaotic Dan

Awesome, I was wondering the same thing myself as there is only 91 octane here too. Thanks for the info

neo_omega

you can always try those octane booster, if you worry about 91 is too low.

Cetchup

Maybe try some MMO (Marvel Mystery Oil) on every fill up. I believe it is 6oz. for like every 10 gallons?

RX7Elmo

MMO is just used as a premix, and it actually decreases octane. Off the counter octane boosters don't do crap. Just go mix in some race gas or mix in some pure xylene (117octane) or toulene (114 octane).

Danny

RonKMiller

Gasoline is gasoline is gasoline, except in Mexico, where it is part water. Trust me, I know.

Actually, you'll make more power on lower octane, as long as you don't pre-detonate. Not to mention you'll save tons of money.

Octane is only the rating of gasoline to resist "knock", pre-detonation, whatever you want to call it.

If your car runs on lower octane without "pinging", use it. The problem with our engine is that it is very difficult to audibly hear. Generally speaking, higher compression engines REQUIRE higher octane.

Your owner's manual specifies premium unleaded.

RonKMiller

kento1

Not to belabor this subject, but a lower octane doesn't necessarily guarantee that you'll make more power than with a higher octane as long as you're not getting detonation. The misconception is that higher octane fuels burn "slower" because of the additives to achieve that octane rating, which use to be the case when tetraethyl lead was the additive for knock resistance. Newer unleaded fuels like Sunoco's GT104 racing fuel burn just as quick as lower octane fuel, but have various additives to resist knock while offering more power for the same amount of fuel.

If you're ever able to hear the knock of detonation with a turbocharged motor, it's already too late.

RonKMiller