I google searched the site but did not find my answer. The manual indicates 87 octane, but I've heard premium is required. Which is it?
actually, they are a very high compression motor 11.5:1Been running my 650 on 87 for two years, and almost 40,000 km. No issues, lots of power. These are not a terribly high compression motor, so high octane is not required to prevent pre-ignition. Remember, octane RETARDS ignition so that fuel does not pre-ignite on the compression stroke.
Many of us wish that we could steer clear of the junk. We can't though because it's all that is available. I think there are a few places in the country where "Real" gas is available but in this part of Tennessee EVERYTHING is that E10 garbage.... Just steer clear of that E10 crap because it'll cost you more in economy loss than what you save at the bowser.
High octane ratings (not actually achieved by the use of octane, but typically through additives like tetraethyl lead, MMT, MTBE, ethanol, etc) do not retard ignition - they increase the fuel's resistance to detonation. Detonation is an explosive combustion of part of the fuel-air mixture that occurs before the flame front initiated by the spark plug has reached it, caused by radiant energy, free radicals leftover from previous combustion cycles, excessive air-fuel mixture temperatures, etc.Been running my 650 on 87 for two years, and almost 40,000 km. No issues, lots of power. These are not a terribly high compression motor, so high octane is not required to prevent pre-ignition. Remember, octane RETARDS ignition so that fuel does not pre-ignite on the compression stroke.
To be exact, high compression ratios and fuel-air mixture temperature are directly related - the higher the compression ratio, other things being equal, the hotter the air-fuel mixture will be as combustion starts and continues. But pretty much all modern engines have efficient cooling mechanisms, yet some still need higher octane fuel. A major factor in whether detonation will occur or not, and what the octane requirement of the engine will be, is the efficiency and speed of combustion in the combustion chamber. The V-Strom has a relatively low CR and pretty efficient combustion chambers that promote fast burning of all of the air-fuel mixture. Modern 600s, having much smaller, more compact combustion chambers (150cc vs 500cc) can run even higher compression ratios (I've seen 13.5:1, IIRC) on regular gasoline without detonation issues. Other things being equal, the larger the combustion chamber the longer it takes the flame front to propagate through the entire air fuel mixture, increasing the chances that some of the air-fuel mixture will detonate before it is burnt normally.actually, they are a very high compression motor 11.5:1
Thew reason they don't need premium is cause the cylinder & head is designed for very efficient and even cooling. there are no "hot spots" within the combustiuon chamber
compression is only 1 factor in ignition of fuel air mixture, temperature is more important
While I appreciate the spirit of this post, Greywolf, and would typically accept your opinion on anything strom as gospel, as stated, I know how my bike runs like you know yours (well, maybe not the "guts" of it like you do), and I'm not imagining it running rougher. Anybody who is aware of mechanical things operate would come to the same conclusion.Have somebody else fill the tank and see if you notice a difference when you don't know what octane is in it. Just knowing what fuel is being used can influence your feelings. There is no way I can think of for a higher octane to produce a smoother running engine unless it is pinging on lower octane fuel and you have not mentioned pinging.
I have the EXACT same experience as you with my 650 (with the exact same skepticism shown from everyone here). My bike pulls better lower in the RPM range on premium, and is noticeably smoother.I typically run premium in my wee.
Most people here who have anything to say on the subject insist that I'm pissing away about $.20 a gallon, and that there is absolutely no reason to do it. Some have even suggested that it is detrimental to the bike to run premium - that regular 'packs more of a punch", and the detonation inhibitors in premium don't do the wee any favors; and Dbuck even says that poor running results from premium (!?!).
In response to this information, have run tankfuls of 87 octane through my bike many times. I do this to make sure that I'm not just imagining things; I mean practically everyone on the 'trooper can't be wrong, right?
My final conclusion? They aren't wrong....about their bikes. But I really don't care what anyone says about their bike, and technical justifications aside (which all make sense), I know my bike, I've ridden it for 26K miles, and it runs smoother on 91 octane.
Everytime I run a tank of 87 through, if I forget I'm doing it, I think "I need to get my throttle bodies sync'd again..." then I remember I'm running regular. Put premium in it, and no issues until I feel compelled to perform this stupid experiment again.
Actually, I'm done with it. It costs me $1.00 more per fill up to experience a smoother running bike - worth every penny to me.
THANK YOU! I knew I could'nt be the only Strommer who experienced this.I have the EXACT same experience as you with my 650 (with the exact same skepticism shown from everyone here). My bike pulls better lower in the RPM range on premium, and is noticeably smoother.
Call it placebo effect, or whatever you want to... I don't really care what you think.The Placebo effect is very real. Unless you do a double blind test or there is pinging, there is no way to validate your impression. You may be absolutely correct but you may be totally wrong. If the money you may save is not important enough to bother with the test, by all means, forget about the suggestion. It might help somebody else though.
One possibility where using premium does result in a better running engine is if that premium grade has a better detergent package than the regular grade. That is all too common out there. http://www.toptiergas.com/ shows brands that have top quality additives in their regular grade fuels. Try one of those if you haven't before.