Hi!

I just got my RX-8 (hell yeah!!) a couple of weeks ago and I love it. The owners manual does mention that we have to use premium unleaded. Is there a danger or difference if I were to use regular for normal driving -- you know given the gas prices and all? I understand using premium at Autobahn speeds, but at typical US speeds? Any thoughts on this? Thanks.

2004 RX-8 MT
Velocity Red Mica
Grand Touring Package

 

tons of thoughts on this
do a search
I'm still using 91

 

I've heard that regular is OK, but I've also heard someone complaining that they got 10mpg when using regular.

91 only for me, I don't want Mazda to be able to come back and tell me "you were using the wrong type of gas, so we won't fix this motor that just exploded" or anything like that.

 

Since the RX-8 intentionally burns a little oil with the gas, you might even try using diesel, or fuel oil. Should save you a buck or two each fill.

 

I split the difference and use mid-grade (89). Last tank gave me 18.6mpg. My mileage has been holding between 18.3 and 19.3 no matter how I drive. I'd like a few more mpg, but such is life.

 

(image a black rx8)
rofl

 

if a manufacture tells u to use premium, then use premium

 

word

and 2 bucks per gallon aint that bad anyways, sure, its way more than were all used to, but it aint that bad, imagine if these thigns ran on water!
________
Homemade handheld vaporizer

 

Look at the thread:

87 Octane - the answer to idle?!?

under RX 8 discussion.

I have been using 87 octane since about 8/12 and will continue. Car runs better. I get 18 mpg in city driving with TCS/DSC turned off and love it

The manual says you must use 87 octane minimum. SO really you may use any of the 3 grades of unleaded.

There are some interesting comments on the thread from racers or people who know racers.

 

Using the handy-dandy conversion calculator built into Google, I converted L/100km into mpg, and found I got 19.6mpg around the city on 95 octane premium with DSC on last week.

 

that is great. It is hot and humid here now and AC is used some but still these figures - especially yours shold make people happy considering competition cars' mileage is really not any better than that.

 

Ive starting using 87 for the last few tanks, and the car runs noticably smoother, and there is absolutely no more exhaust smell, might be coincidence, but im sticking with 87

 

I've tried 87 octane and I realized that the car runs fine. The idling is a little rougher and accelerating is a little slower, but not by much. The engine also seem louder when running on 87. I decided to switch back to 91 octane and realized a big difference. The engine runs and accelerates much more smoother. It seems that my experience is different from others that say using 87 is smoother. Then again, I have the automatic, but I'm sticking with premium. It just feels so much better.

 

wow all this stuff is probably in people's heads..

some one here said the EXACT reverse about using 87...

 

I did. I've told everyone that MY CAR runs better on 87. The engine was missing and sooting and sluggish on 91 and it was suggested to go to a lower grade because it burned cleaner and faster. Apparently it was true. I know that there are conflicting tales on here where some are burning 91 and say they tried 87 with bad results. I cannot speak for them. I also see that some have said we have to burn premium or void the warranty - that is not the case. I say, let them spend more and think they are doing a good thing. Can't MAKE anybody do something, right?

 

I'm not convinced premium is better. See my sig. Some earlier dyno runs I've seen said the same (not much diff)

 

its a plot! Manufactures tells us to use premium to increase profits for the oil industry. In return, they get incentives.

 

I wonder how the new ECU after port settings are affecting the required octane needed. The problem is if you use 87 how much does the ECU have to compensate by retarding the spark to reduce the tendency to knock. Another factor may be the alcohol content. I know here in the Chicago the Sh*t gas they sell will make any car run poorly. I am not sure I would know what a knock sound would sound like in a RX8 engine. I am going to stick to 91 until I have a few thousand on her.