fastone

Well we all feel the high prices for 93 Octane gas at the pumps, so has anybody tried to run there car with Regular Gas or Mid Grade fuel.
If so what differents have you felt in the car, or would it damage the engine.



:D

legokcen

I've used regular most of the time. Occasionally I'll use 93 during track time or autocrosses. Nothing different. A little smoother idle maybe, but I really can't tell.

Katchoo

No problem...use middle or regular all the time.

Krankor

So then why do they recommend premium?

Krankor
05 Shinka 6MT

Tracker

i am at a bit of a cross-roads myself here, your saying that the car runs fine on reguar gas? and what is your definitin of regular? here in Las Vegas its 87 octane and some stations its as low as 85.. if i recall reading in the owners manual, it said 95 octane, so i was thinking about buying premium (91) and using an octane booster, alos out here they are starting to offer an alternative fuel.. E85 thats accually cheaper that regular, i do wish i could run that (85% ethanol = 105 rated octane) any suggestions? id rather un the cheap stuff, cause gas prices here are insane, and my gas mileage isnt what the epa said (15 MPG)

so in my first thread ive highjacked someones thread.. only about 25% though :-D

Tracker

Tamas

iTrader: (1)

Manual says 91 is recommended, regular (min. 87) is acceptable.
I'm using 87 most of the time, and the car runs fine, no noticeable power loss and it idles smooth. I get also slightly better gas mileage than with premium, just like several other people.

JeRKy 8 Owner

Now that the hurricane has raised the already bullshit gas prices, I'm even considering dropping down to regular even though we're technically not talking about a lot more money here.

legokcen

Most new high performance high compression piston engines require premium so that they don't knock. This is a higher compression rotary engine, but it won't knock with lower octanes. Since the newer high performance mainstream cars are asking for 93 octane, I believe Mazda asks the same to be viewed as a high performance car/engine. This is my personal belief. Flame on if you must......

Brice-RX8

I believe RotaryGod has said many times that over the years and including now he has used nothing but 87 in his cars, so that is what I am using. When I uses 87 octane my car starts faster, throttle response is better, less black soot in the tailpipes, and slighly better gas mileage. I am sticking with the 87.

Oh and by the way, do a search, the 87 vs 93 and all other topics on gas have been discussed hundreds or times.

merdy05

if i'm not mistaken i thought that the manual said that 91 is the most acceptable, but around here you can't find 91 it's either 87, 89, or 93. anyways i almost swore that the book said nothing lower than 89...so it's it really okay to use 87 in the car? i didn't want it to start idle rough or nething...

Nubo

It's one thing to debate the relative merits and properties of gasoline grades. It's another thing to swear up and down that the manual says something WHEN IT CLEARLY DOES NOT. For crying out loud, open the damn thing!

GotBass

Premium is always 20 cents a gallon more than regular in chicagoland. That works out to around 3 bucks when you fill up. If thats gonna make or break you you probably bought the wrong car.

Rx8bydocabe

come on man, he almost swore :p

aggietiff28

LOL...you can read it in the manual...or I noticed the other day that there is a sticker inside the fuel door that tells you what they recommend and also what is the lowest you can go.

Psylence

87 wont break your engine. Thats why cars have these newfangled things called "knock sensors."

I have company gas cards for damn near every station.. and I just started fillin it up with the "cheap" **** anyway. Why waste the money, *anyone's money* on premium if you don't need it? I have had many cars.. and some of them needed premium, in that you could TELL when you put cheap gas in. MPG would drop off drastically and power would be lost.
Rx8 does neither, at least in my experience. I whipped the crap out of my last tank of 89, and got noticeably better mileage. No power loss, no funky noises.. if anything else, slightly better throttle response. Which makes sense, going by the shape of the combustion chamber in a rotary engine.. I can def. see why 87-89 would be better in a rotary.

Of course, ymmv.

mikeb

rather be safe than sorry
I have used only 91 for two years

wedge357

I experimented, last time I put gas in I used 89 octane and did not see anything wrong happening (no knocking, no slower throttle, no engine crapping out on me). Then this last time I went back to 93 octane, no difference at all. I think for now I'll use 89, then later do another experiment with 87 vs 89 to see if I can go lower. i'll let you guys know.

MTLbroker

I use regular from day 1. No adververse short term effects.

conedodger

This is my second tank of Sunoco regular (87). No issues so far. Seems to pull the same w/ no pinging. I might even be getting slightly better mileage. Gas just went up to $3.09 here for 87 so I'm not complaining one bit. :D

kmorris

I usually use 89, though when prices are up I'll use 87 and have never had any problems.

I don't have the manual handy right now, but I don't recall anything about the rx-8 being compatible with E85 and thus would NOT use it unless you check for sure about compatibility.

Nubo

Lol, I can't find my slack-cutter this morning

I guess everyone is different. To me, the fuel grade requirement is something you should really be finding out before you get gas the first time. But then again I'm from the "lowest octane that works" school. I guess someone from the "high octane can't hurt" school might not seek out that info. On the other hand, part of the fun of a new car to me is reading the manual. Though it's not as fun as it used to be, with all of the !'s inside triangles and repeated death warnings

KWS

Okay, when gas was "cheap" (cheaper?) 91 octane was 20 cents more expensive that 87 octane. Now 91 octane is still 20 cents more expensive that 87 octane. That 2 bucks more for 10 gallons when gas was cheap, and it still 2 bucks more now that gas is expensive.

89 octane costs a dime more a gallon so you save a buck on 10 gallons.

I've decided to stick with the 91 octane.

oreo

So,
the real reson is...
...
...
...
?

dwynne

I am on my second test tank of mid-grade Chevron. Still the same crummy mileage commuting to work (13-15mpg), but no NOTICED ill effects from saving $0.10 per gallon. I might try the "rot gut" regular next time just to see.

The hurricane has changed (or will change) a lot of attitudes on gas - it was folks were b!tching about the price, now folks are going to have to worry if you can even GET gas at any price.....

Dennis

wedge357

I put approx 14gal each time I fill up and it's weekly. At 20cents differential between 87 and 93octane that's $2.80. Multiply this with 52 weeks a year and you're saving at least $145/year on gas or about another 4 tankful of gasoline. That's still quite a chunk of change considering premium is "recommended" and not "required". I was putting 93octane but will switch to 89 or even 87 soon. As long as the car runs well I do not have a problem with it. I think I can put that $145 to good use...