Spazzychaz

Well, I ran a few searches for this topic already and I am sure I just did not put the right search criteria in, so go easy on ne for reaskign this. I know that the dealer says that high octane fuel should be used to for the Rx8. i wanted to check if this is true. I have read a few threads where people have used 87 octane gas. I am just curious as to what type of gas everyone uses and if the high octane is really needed for an unmodified Rx. Thank you in advance.

KRNrx8Driver

I heard from my dealer that i HAD to use 87 octane so i got a full tank of 87 gas when i picked it up -.- i HATED IT it felt alot different then the rx-8s i test drove so i was pissed at first but i already signed for it and i was actually kinda disappointed cuz it didnt have as much of a punch as i expected at high revs but iono after putting in 92 (this was back in iowa) octane it felt good and all was well in the rotary world =). Currently i'm in GA so i use 93 octane and its well worth it.

expo1

I have been using 89 Octane and have had no issues. I now have 85,000 miles on my 8. I only use 93 Octane during Track weekends.

nycgps

iTrader: (1)

it really depends, some had issues, some dont.

If you have problems, try 89, if problem goes away, stick with it.

Im a lazy *** so I just use 93 only, worry free. yes I paid maybe 10-20 cents more per gallon but again, Im Lazy

Raptor75

I've been running 87 since I got the car. Ran 93 for a tank full and saw no noticeable increase in performance it actually had a little less MPG. Mobile Fuel.

Rotary's run well on low octane because of the combustion chamber design. Higher octane's only value is to increase resistance to knock. If your car is not knocking then you are fine using 87. I have seen no evidents that the knock sensor which retards spake advance produces any more power using the 93 octane then 87 in the RX.

There are a few that must run 93 for knock or others that feel safer running 93 which is cool. My self, I would prefer to invest the extra couple of thousand that 93 would cost me over the live of the car into some nice mods. That's just me.

If you feel better going with 93 in won't hurt anything but your pocket book.

fredw1

I have been using 89 for two years. No problems. Seems to be a good compromise.

shaunv74

I used 89 for about 2 years on highway driving 80 miles a day with no problems. I now have 53K miles on my car. Now that I don't have to drive to work every day I've switched to 91/93 octane. Still no problems. In the owners manual it tells you 91 is preferred and 89 is acceptable with reduced performance.

ZoomZoomH

iTrader: (1)

try a tank of 87 and see how the car feels, if it feels fine, you should be ok to use it

i use only 93, just because :D

ken-x8

I'm pretty well institutionalized. The manual says at least 91, so that's what I use. Actually 93, since stations around here have 87, 89 and 93, and I'm not **** enough to go 50/50 between 89 and 93.

I always try to use name brand gas. I also will not refuel if there's a tanker at the station.

Ken

mafenton

Here in Los Angeles the highest octane we can get in 91. I have put 89 in it a few times, but in the grand scheme of things paying 8-10 cents more a gallon for the higher octane (which comes out to less than $2.00 a fill-up) and the better performance is more than worth it

Fanman

I use 91 only. I once accidently put 87 in, and when I revved on the freeway to pass a few other cars, my CEL came on. Since I put 91 back in no problems.

Razz1

91 all the way baby...............

Follow the mfgr. recomendation.

devildog1679

I agree, lets say you drive 150K over the life of the car. 16 mpg at an extra .20 per gallon for 93 thats only $1,875 over 7.5 years, that is if you drive 20K per year. Cheaper than a screwed up engine because you wanted to save a few cents.

RotaryP7

I use the best.. And around here.. 93 is the best.. My car needs the best. Best is best..

TimzSI

huh, I just assumed 93 was a no-brainer, so its all I've been using. Whats the rensis' compression ratio, 11:0? I think maybe I'll try a tank of 89 in the coming months...

valpac

iTrader: (2)

Nothing but 93 in my car. And no gas related issues. FWIW, I used to use BP but now only Shell V-Power or Quik Trip. Here's some interesting reading..

http://www.toptiergas.com/retailers.html

nycgps

iTrader: (1)

I think the toptiergas thing is more torwards the marketing side than real affect.

Just my opinion.

Raptor75

My RX Manuel says use nothing less then 87 octane. It states less then 91 could result in a slight performance reduction. So your are following the manufacture recommendation using 87 octane and many here with a high level of technical knowledge confirm that there is no real gains with 91-93 octane in the vast majority of 8s.

Peace of mind is a great thing but I'll be looking to through my savings into a nice turbo down the road, then use 93 when I really have to.

Silver_Surfer

87 Here! no issues. Tried 92 and switched and fourth

alnielsen

iTrader: (4)

I agree to a point. What it tells you is that these fuels meet a certain level of quality. That doesn't mean that these or other fuels don't exceed these levels.

I've been using 87 octane for quite a while. The people that have been having perfomance problems when using a non-premium fuel probably haven't given the ECU enough time to adjust the timing for the lower octane. And, in my experiance, rotarys love a lower octane fuel.

ken-x8

Rather than quality, it means they have enough extra detergent to make up for shortcomings in the fuel systems made by those four manufacturers.

Probably a good reason to not buy any of those brand cars.

Ken

alcimedes

In my experience if you reset the ECU when filling up on a new octane of gas, then give it a full tank to learn, then one more tank to actually drive with you'll get a better idea of what your car likes or does like.

Granted it takes a while to go through three different octane levels at two tanks each this way, but it was worth it in my opinion.

I found that my car ran better on lower octane fuel than on high octane fuel, and got a few mpg higher as well. Your results may vary.

I should also mention that this is only from good gas stations, none of this "Bob's gas shack" crap.

Spazzychaz

Thank you all for the information from experience. I really appreciate it.

tksnobords

the compression is 10.1 i only use the highest octane i can get from pump gas stations. but i am tryin to find out anyone information about running higher octane than 93. i have just made a post about the octane levels

Phantom Menace

Depends on the year. I believe, and have been told by the my local dealer, that older models--up to and including 2005--RECOMMEND 91 but the engine could, concieveably, run fine on lower ratings. Newer models, 2006+, the manual no longer uses the "RECOMMENDED" language and, instead, prescirbes a minimum of 91.

IMHO, the price of using the cheaper nozzel, however large that sum may equate after several years, does not justify peace of mind and the feeling of "spoiling" the car...