Fuel Octane

[MMcc]

Octane

I just double checked my 2011 RT-S. The label by the gas fill said minimum 87 octane. Have tried 91 non-ethanol highest available in our part of MN, $0.50 per gallon difference. I did not notice any difference in fuel economy. Always used mid-grade or premium in my 08 RS/GS.

 

[capt.jim]

If you go to pure-gas.org you can find if there is a station in your area that sells non ethanol in Canada or the U.S.

 

[Bob Denman]

BTW, using premium fuel will only cost you about $100 more a year if you ride 12,000 miles a year.

:clap: Most of us wouldn't miss it when it's only spent about a dollar at a time... :thumbup:

 

[Tonga]

So True

I use what is recommended by the manufacturer. For the RT, that is 91 octane (US). In this area our premium is actually 93 octane. The RT will run on lower grades, but it will not run as well. This is not some half-baked theory or a conspiracy hatched by the oil companies to get more of your bucks, it is an engineering fact. When running lower grade fuels, the RT will adjust the engine timing accordingly, to prevent knocking. This reduces performance. If this fits your style of riding, fine, but I like a more spirited ride.

BTW, using premium fuel will only cost you about $100 more a year if you ride 12,000 miles a year.

I agree with you Scotty. If recommended then use it. For the back yard engineers, use what ever suits your personal needs. The RT has a higher compression engine then the GS does and detonation is a killer. Many Miata guys that I know think of saving a few bucks when filling up as the Miata recommends 91 as well. I want any vehicle I own to run at it's best and last longer!!

 

[Roadkill]

manual spec 87 octane

+I've used the manual spec 87 octane in my '08 GS since day 1, including aggressive driving, without ill effect and will continue to do so.

Ride on.
Roadkill

 

[SPYD1]

I have tried them all with no improved or lack of performance. The manual does say 87 for RS/GS/:dontknow:

 

[Some Guy]

+I've used the manual spec 87 octane in my '08 GS since day 1, including aggressive driving, without ill effect and will continue to do so.

Ride on.
Roadkill

Hey Roadkill..what do YOU know?!

...just how many miles do you have on motorcycles? The last I knew it was only TWO MILLION or so! So...what do YOU know?! :joke:

Rock on bro! :bowdown:

 

[wyliec]

+I've used the manual spec 87 octane in my '08 GS since day 1, including aggressive driving, without ill effect and will continue to do so.

Ride on.
Roadkill

:thumbup: I ran 93 for awhile and noticed no difference between 87 and 93 in mpg or performance, placebo or actual.

 

[MikeinGA]

I agree with you Scotty. If recommended then use it. For the back yard engineers, use what ever suits your personal needs. The RT has a higher compression engine then the GS does and detonation is a killer. Many Miata guys that I know think of saving a few bucks when filling up as the Miata recommends 91 as well. I want any vehicle I own to run at it's best and last longer!!

What is the compession ratio of RT?

Mike

 

[NancysToy]

What is the compession ratio of RT?

Mike

It is advertised as 12.2:1, but that may not be the effective compression ratio, just the calculated value.

 

[zbunker]

Ok peeps, what octane are u using? Manual says minimum 91??

On my 2012 RT I run a mix, a tank of 87, then 91, then 89. I don't let the tank run too low, so the fuel mixes up. (So I get some sort of an average octane ) I try to change brands too. Perhaps just an idiosyncrasy, but I found with my autos, if I always filled up with the same brand all the time (89 octane), changing brands had a difference in performance; usually worse.(my '91 ford van hated shell fuel)
Lord knows if this is good or bad for the Baby
My 2012 has less than 800 miles on it, and from what I heard the 'break in' mileage usually is in the low 20's and as the machine 'matures' the mileage increases. I can only hope my machine is an 'early bloomer'

 

[Bob Denman]

I've always run 93, but tried some 89 as an experiment...
I ran the tank real low several times to drain it out as much as I dared... :shocked:
The 89 octane didn't "pull" as well from lower rpms; I felt the need to downshift where I normally would not.
So it's 91 at least for me! :2thumbs:

 

[ulflyer]

I'm definitely not an agressive rider and I use 87 in the RT. Alternated with high octane and regular for a few tanks and couldn't tell a bit of diff.

 

[BLUEKNIGHT911]

OCTANE OCTANE OCTANE

Read the latest issue of Road & Track very informative and understandable......Mike....:thumbup:

 

[PCBeachBum]

I use 93 octane.

 

[mastertek2000]

I've always used 93

 

[Recluze]

I use the highest I can get usually 91.

The Star Tron additive got my attention so I did a little research. It is mostly naptha which is a solvent and an octane booster and a wee bit of secret stuff. It should do some good. I intend to put some in my boat which has been sitting a while. That and some 100 octane that I can get locally should fix the boat up.

Most gas additives contain alcohol as their solvent. As near as I can tell you don't want to do this. More alcohol could do some bad things to your engine so be careful. You can call up the MSDS on any of these on the internet. Supposedly, as I only tried a couple.

Let me go on record as saying I hate ethanol. What lame brain made the decision to burn our food source in our cars is a mystery to me. To replace gasoline with ethanol would require planting the entire surface area of the US in corn. I am not oppose to making ethanol out of saw grass or some other biomass. Just don't put my food in your gas tank. Sorry all you mid western corn growers: Love corn just want to eat it not burn it. As for the government aid you get to do this you are welcome to it.

Aircraft are exempt from using ethanol gas. I wonder why with my tounge in my cheek. I wonder if we could put a couple of stubbies on a Spyder and get it classified as a low flying aircraft. Fueling up at the local air strip is a bit of a hassle these days as they have increased security.

My Spyder gets about 30mpg. Once I leave the late great state of California and go say to Montana that will jump up to the high 30's sometimes forties. I assume the bike has more power when burning the 'better' fuel they have there but I have no way of measuring that.

Sorry if I took the octane thread in a different direction. It is often better just to ignore me.

 

[bluestratos]

I use the top grade but I have tried regular on occasion and can feel the change dramatically if the tank is near empty when I put it in. The engine works fine on all fuels but the timing is changed by the computer based on how much knock the engine has. More timing = more power when you need it and better fuel milage if you drive conservatively. In the good old days we would fill the tanks with the good stuff and add 1% Acetone to the gas as well, this allowed us to move the timing up considerably, as much as 5 degrees more advance from factory settings. To test we took the vehical to the a steep hill and part way along we would push the throttle in and listen for ping or knock. A bit of ping was acceptable on the hill, it just meant we were as close as we can be for timing advance. Of course we would also recurve the distributer springs as well.

This minor change can yield amazing results. I had a 460 Ford come into my shop, the owner was complaining about bad gas milage, poor performance and over all ran rough. I did a standard tune up with all new performance parts and this made a world of difference but then I checked the timing and it was set at -1 degrees. The manual called for 10 but also required premium fuel. The owner ran regular and some one had lowered the timing due to run on and ping. I also discovered that his vacuum advance was not working which made matters that much worse.

I drained the tank, changed the filter, installed a new vacuum advance and put 10 gals of premium ( no aceton this time) then set the timing to 15. This test drive I laid rubber and accelerated like a bat out of hell, even got a bit of a chirp going into 2nd on the auto tranny. The Guy was estatic, even insisted on giving me a tip. I had explained that the extra he pays for fuel will be gained back by MPG as long as he drove as he normally does. 2 months later the guy was complaining that the engine was knocking and he wanted me to fix it under warranty. I found out he had switched back to regular as premium was to expensive. I reset the timing to 3 degrees and all was good.

I also look for station with no methanal (Pacific 66 in my area). This give better gas and power as well and I have tested this many times so now, if I have to use fuel with methane I add Star Tron additive.

 

[Littlebadwolf]

I've been running 89 with an octane booster in mine...no problems.