87 oct of any reputable brand.....it's gas not not fine wine. As long as you have gas from a reputable band, you can't tell the difference as to what is in your tank.

 

i've been told to stay with the same brand over and over, and i chose sheel because it has the least amount of ethanol in it. just what i've heard.

 

Ive never used anything but Chevron and my baby has never been to the dealership *knock on wood*

 

with you there buddy! All i use! works fine for me!

 

I put Costco (whoever they buy) 91 in my tank and add FP Plus.

 

I've switched off of Shell V-power since they introduced the new nitrogen enriched detergents. Since they started my gas mileage has gone down. I switched to AM/PM and my gas mileage immediately shot back up. Better fuel mileage=more power.

 

anyone using 10% ethanol for a long period of time?

 

10% ethenol since day one for 32,000 miles... not a very long time but some amount of time
no problems either *knock on wood*

 

Always. I don't have a choice in California.

 

yeeep! all our fues have ethanol, its too bad, we don't have 93 octane though! i wonder what my 8 would feel like running that!

 

are you using 10% ethenol on 90 or 94+ octane?

 

how about you? at what octane of 10% ethenol?

 

shell v-power or mobil 93 .... im getting 270 miles to a full tank in city driving and thats wit me driving my car like its stolen... not a miligram of carbon in my exhaust..lol!

 

i use it with 93 octane... i've never even heard of 90 or 94+

 

90, 94+ are mostly found on E10. California enforced 10% ethanol on all the gas they sell.

 

I recently bought an 8, so I haven't put in but 3 tanks of gas. However, I CAN speak to 3.5 years of premium fuel in my 04 Acura TL... Chevron Premium is the winner BY FAR. I find that it's almost always cheaper than Shell and the Techron really does make a difference.

I experimented by using BP premium for about a month, then went back to Chevron. I have done this several times and noticed my engine running a bit smoother with the Chevron Premium.

Every 6-9 months I will run the tank to empty, throw in a bottle of Techron, and fill up with Chevron Premium... the car purrs for weeks.

RaceTrac and QT also have high quality fuels. These are the only two companies I know of that GUARANTEE no water is in their fuel. They randomly sample gas at all their stations several times per year.

 

I thought the brand was making a difference but I realized it was not that. I found that which individual station you are talking about is at least as important as the brand. The busiest station near me on the main road is an Exxon Mobile station selling 93 octane. The car runs terrible on this. The station has been there forever and the area is a lowland that occasionally floods in heavy rain. It has nothing to do with the brand Exxon, it is the station. I have found this at other places as well. The RX-8 is probably just more fickle about these things then the majority of mass produced cars that fill up there. Ignoring some known bad stations.....I cant detect or measure any difference among the actual brands of gas at other stations.

 

its a mental thing for some, like me i think

 

anyone in California using octane 90 E10 fuel?

 

I've recently topped up with 90oct. 10% ethanol fuel. runs fine so far. On cooler days, I run 87. But in the summer humid, 91 oct is my preference. Car runs strong and hard.

 

I always use Quiktrip gas because they are not privately owned.


I try to support Mom and Pop businesses in many things but in Atlanta a few years back there were a number of Mom and Pop gas stations that added water to their gas so I stay away from all of them rightly or wrongly.

I only use premium too.

 

I don't know about where you guys live but a good friend of mine owns many of the convenience stores around here that all operate under one name. However, some of them sell gas under the Shell name brand and some under a generic name. This guy's family also owns the oil company that supplies these stations and the same trucks refuel the underground tanks at every one of the stores. Yet, the gas is a penny or two cheaper at the stores that don't use the Shell brand name. So, tell me which is better. Shell brand V-power gas or a generic convenience store brand gas that is pumping gas that came out of the same truck?

So far, I've only filled up with 93 octane and have topped it off with 89 a couple of times but I stopped worrying so much about what brand it was when I saw the little dance they do with the brand names.

Good to know some people are getting away with 87 octane though. That info may come in handy as gas prices continue to go up.

 

The same delivery services perhaps, but when they fill those tanks, each one has a special additive package that is added. That is the only real difference.

 

Pretty much the same as with 87.

All major bands say that the detergent used in their regular gas is sufficient to keep your engine running clean for the life of it. The premium brands have higher levels of detergents designed to remove built up deposits. If you have been using a good brand for the life of the car then the extra detergent of premium becomes unnecessary.

As for Octane the higher ratings only prevent knocking and if your RX-8 is not knocking then your just throwing money out your tail pipe. Now you can say that the knock sensor will retard timing and decrease performance but I have yet to see any evidence of this personally or through testing. Actually the Rotary runs better on lower octane because of its long slender combustion chamber. Race Rotors will run with octane as low as 80.

So put want you want in but the reality of the situation is that 87 from a good brand will server your car as well as 93 and save you a far deal of money over the life of the car. I do agree that fresh gas is better then old so a high volume station makes sense to buy from. Enjoy.

 

thank you. did you notice any mpg drop at all? some say e10 would not last as far as regular premium... did you find that at all?