MRey

what type of gas and what octane do you run in a rx7? N/A and a turbo? Is chevron good for turbos?

jeremy1

run the lowest for n/as and the highest for turbos
i am on the safe side and run any name brand gasoline but supposedly the other gas is the same.

Dan H

87 octane for my NA

Runs best on that stuff.

Icemark

87 for a N/A
91-93 for a stock Turbo

j200pruf

iTrader: (4)

87 for my n/a, and I would use super in a turbo. And yes Chevron is good gas to put in your 7. That's all I put in mine (but thats only cuz I work at one and get my gas for free, even though I'm not supposed too )

Evil Aviator

87 R+M/2 for NA, 87 R+M/2 for TII. If in doubt, read the owner's manual.

Evil Aviator

BTW, super unleaded is a waste of money.

jsotelo

87 runs MUCH better in my N/A than super

MRey

so ice mark says i should run 91-93 octane in my turbo

but evil aviator says i should run 87?

which one is most prefered? cuz i know both these guys are knowledgeable?

QUAID

Ok so why is super a waste of money on a turbo?

poor college student

aviator... is that advice for a stock setup? or a larger power turbo setup... b/c if you're running high boost, i don't think you want to be running 87 octane, unless i've got something mixed up.... care to clarify?

Josepi

I've had detonation under full boost on a stock setup using 87 oct gas. Of course it was around 96-100 degrees outside with the AC on full blast.

CrackHeadMel

iTrader: (2)

is this a typo?

MRey

i was wondering if that was a typo to

but then on his next reply he said that super unleaded is a waste of money

1987RX7guy

iTrader: (3)

bot the n/a and TII were meant to use 87 octane from the factory. If you have a nice big fat turbo though I don't think you should stay with 87.

Santiago

Juan

iTrader: (28)

If you read the Owners Manual that came with the car, assuming you have one, says to use 87 for Turbo and Non-turbo cars. If your TII is bone stock and you're not racing people, then you should be fine with 87. If your TII has a free flowing exhaust, then use 91 or 93. N/As run better with 87.

Mazda actually won a race running 87 while their competition ran higher octane fuel. The other teams nearly died when they heard Mazda beat them running 87 octane fuel.

MRey

well all i have is a intake filter so i guess i'll just run 87 octane for now

bingoboy

well NA's run noticably better on lower octane fuel. I don't know how turbos treat it, but I think I would be willing to spend the extra dollar per fillup in the hopes of my engine lasting longer if I had one.

edit: oh also, if you're going to be driving the car really hard you should probably put high octane in it for safety's sake.

J-Rat

iTrader: (2)

Not if your modded it isnt!

I can handle the slight decrease in performance for the added safety margin against detonation that Super Unleaded provides.

Jarrett

J-Rat

iTrader: (2)

No **** sherlock....

Jarrett

Evil Aviator

LOL, it probably looks like Chinese to some of you, so I will explain. There are different methods for calculating the octane rating of gasoline. Basically, the octane rating is the anti-knock rating of a fuel based on the operating condition of the engine. It is called "octane" because the rating is relative to the properties of iso-octane, even though the fuel may not even have any octane in it.

Here are the basic types of octane numbers. Please excuse me for simplifying things.
RON = Research Octane Number = Knock rating at cruise
MON = Motor Octane Number = Knock rating under load
SON = Supercharged Octane Number = Knock rating under boost
PON = Pump Octane Number = The average of RON and MON = (RON+MON)/2, but usually shown on the pump as "The R+M/2 Method".

The USA uses PON, while most other countries use RON. As you may have guessed, since there is less chance knocking at cruise than there is at an average of cruise & load, RON is always higher than PON for the same fuel. This is why it appears that other countries have higher octane fuel than the US.

Anyway, both the NA and TII 2Gen RX-7 are rated for a minimum of 87 PON. You can use higher octane if you like, but in most cases it's a waste of money. Some reasons for increasing the octane include, but are not limited to, atmospheric conditions (extremely hot, dry, high barometric pressure), driving conditions (load, especially pulling a trailer or going up a steep hill), increased boost levels from stock, worn engine and/or turbocharger, or engine out of tune. If you notice any knocking, then by all means switch to a higher octane fuel.

What you do to your car beyond stock trim is your responsibility to maintain as appropriate. It is not possible for anybody to specify a particular octane fuel for every known combination of car parts and driving conditions known to mankind. BTW, just for some FYI mathematical trivia, if you have 400 possible engine modifications, there are more possible combinations than there are estimated atoms in the universe.

That's not necessarily true. It depends on the boost level, turbo efficiency, intercooler efficiency, engine tune, water injection, and many other factors. However, most people would probably want to use a higher octane fuel with a large turbo to achieve higher boost levels.

You are not necessarily getting less performance with super unleaded if you are running a lot of boost. Most pump gas is more or less 19,000 BTU/lb (btw, this is the power rating, while octane is just a knock rating). Super unleaded may be a little less, but if you can run more boost with it, then you will have more overall power. As a comparison, methanol is only about 9,800 BTU/lb, which sounds wimpy, but with a 115 RON and 4.5:1 AFR you can run tons of it through your engine at high boost and blow the doors off a similar car running on super unleaded pump gas.

MRey

damnn he kind of got all of us on this one...

thanks evilaviator for schooling us =p

J-Rat

iTrader: (2)

Actually, this was all explained in about 100 other posts.

Jarrett

https://www.rx7club.com/forum/showth...ghlight=Octane