Since I'm not much of a risk-taker with my engine and I'm in CA, I go for Chevron premium with techron every time

 

any gas will be fine

 

Ethanol has about 70% the energy content of gas maybe a little less. So at a 10% concentration you will get about 97% the energy content of pure gas. This means about 3% less fuel mileage.

If you normally got 200 miles per tank fuel with pure gas you would drop to about 196 miles with 10% ethanol.

 

chevron high test. Actually read an article in popular mechanics that techron actually works.

 

whatevers cheap and around when my light turns on?

 

good calculation. that's what I am looking for. 3% less mileage is pretty acceptable.

 

This sounds like bad advice to me. does anyone really believe higher octane gas is a CURE for knocking? No, you use it to prevent it from happening.

Futhermore the Star Mazda series uses 96 octane. what are you talking about with racing 80?

I can't imagine why people are obsessing over brand name or other things and then don't even follow the basic guidelines the manufacturer laid out in the manual, which says 91 or better, plain as day.

 

pull the room fuse, fill up with 87 BP or Shell gas, put room fuse back in, do brake dance.

Will run just as good if not better than before when you were using 93 and you will see a 5% or more increase in gas mileage.

Ive tested it and so have many other smart people around here.

The ecu will account for whatever octane you put in the car as long as it is programmed for it. If you have been using 93 and the ecu is learned for it, then putting straight 87 in will result in possible knocking, but if you re-learn the ecu when you put the 87 in, no issues.

 

Which fuse are we talking about here? room fuse?

I know ECU will automatically recalculate and compensate the octane, but I didn't know you have to reset it.

 

yes the room fuse, thats whats posted :P

bottom fuse interior 15a

ecu will recalculate over time, but will instantly recalculate if you pull the fuse and reset. you dont want it to happen "over time" when knocking is a risk

 

I usually try to fill up before that dreaded light comes on. Our gas guzzler makes me nervous.

 

it'd be pretty nice if california offered octane higher than 91...i hate our strict emissions laws!

 

I did the calculation. When the light comes out, we should have about 10L or 2.5 gallons gas left. There for, it should be enough for enough 30~40 miles or 50km~60km (base on my 17.5 mpg).

 

Is it the Fuel Injector one? the one listed in owner's manual as # 33?

Thank you very much.

 

hey guys i hope to increase my mileage by doing the room fuse thingy, otherwise i am buying a hybrid camry

 

yah. what he says.

 

If you don't fully understand the rotary I can see how you might think this is bad advise. What I say here is nothing new, this is pretty common knowledge and if you do a little research you will also understand. The quicker burn rate of lower octane fuel is better suited for the long narrow combustion chamber of a rotary engine and will produce more power. Now that advantage could be off set by the higher compression ratio of the 8's rotary. Some say yes some say no, as stated previously I have seen no figures to back up either statement. I have read enough from people with greater knowledge then mine in regards to the rotary that I lean towards the lower octane group. I also believe that there are few RX-8s on the road delivering the compression ratio stated by the factor when new.

By the way I have a 05 and my manual says it is fine to use 87....plain as day. Mazda changed it in later years because a few cars were developing knock probably because of carbon deposits. The easies way for Mazda to address these few cars was to put a blanket statement that the car required 91 octane. Guess what your engine and mine are the same so.....you connect the dots.

 

That wasn't a paid advertisement

 

Really? 05 says 87? Thank you. it's very nice to know.

I am going to try out the E10 octane 90 with ECU reset once I broke-in my 8. It's more than 13% cheaper than 91 octane from any gas stations yet very close to 91.

I have a friend who is very much into cars gave me similar statement about the octane number.

 

I always used 93 since I got the car, almost 1 year ago. I put in 89 to see if I get any better mpg and to see what the performance is like. I did not pull the fuse or reset anything and I am not experiencing any knocks at any RPM. The throttle feels different(placebo?). If feels like I need to apply more throttle then before to go faster, what use to need 20% throttle now needs 25%-30% throttle. However, if I apply 60% - 70% throttle, it feels the same as 93. I will comment on MPG probablly middle of next week. Then I will also fillup with 87, pull the fuse and perform the reset. I'll be a guinea pig for those who dont want to try it

 

Glad I could help, I've switched gas over the Octane range and tracked the mileage with similar driving routes and style and never saw any difference in mileage between octanes. I also have filled up in Michigan a few times which offers 100% pure gas and did not notice any significant difference in mileage but this was not a controlled test with similar driving so that could have masked it.

Now that being said, when I switched it was for only a tank full at a time and I never reset the ECM which could make a difference. I will give it a try and report back.

 

you been very helpful indeed.

It is the Fuel Injector Fuse, right? Marked as #33 in fuse box?

 

It's true that higher octane fuels burn slightly slower, so I can see the argument for going with a lower octane - some of the smaller 4 bang motors prefer lower octanes for this reason (short stroke doesn't like a long burning fuel).

But I am no chemist - V-power every tank

 

i try to get 91 at chevron most of the time. If i'm really low and have to get gas....there are a lot of 76's around so..

 

Shell....preferably

BUt i'll take SUNOCO, Mobil or Texaco