mikstr

Not sure about how things work in the US but when I worked for the oil company (a subsidiary of Sunoco), they were serving up a 6% mix at the time with hopes of getting it up higher (the main thing holding them back were supply shortages).

All isn't bad with ethanol as its solent properties keep the engine internals clean and in the winter months (for those places that have winter, lol, like up here in Canada), it saves you from having to use gas line anti-freeze.

Another downside of the stuff, however, is that it is Hydroscopic (think that`s the word), meaning it absorbs water from the air so over time (so gasoline/ethanol mix actually increases in water content over time if stored for prolonged periods).

swordfish

thanks for posting. I was starting to think I was taking crazy pills. I couldn't believe nobody else was having the same symptoms as me on the 87. was thinking; "was it in my head? maybe it was something else? but it did run better after I switched back right? thanks for reaffirming my conclusions.

malahhaor

I am on my first tank of 89 after always using 93 and I must say that the bike does not run as crisp. It feels a bit tamed.
But I did notice that at idle my RPMs are not as jumpy. With 93 after bike gets hot it would idle around 1200 and jump up and down between 1K to 1400rpms. It now still jumps but by half of what it used to.
Also now it nearly stalls out when I get off the gass, it goes down to a tad under 1K.
Any thoughts? Is it gass related or coincidence?

JamieDaugherty

Try a tank or two of premium.... I'll bet you won't go back.

mikstr

I ran premium at first and switched to regular. Only change was I kept more money in my wallet.

When I had the cams and heads done, I discussed the matter with the guy who did the mods and he clearly recommended 87, said there was no need for premium.

Based on what some of you write, I am led to believe you are getting sh**y gas.

JamieDaugherty

I don't think it has anything to do with the gas [note: the newer regular gas with ethanol sucks... everywhere]. I think it's a case of "you don't know what you don't know". These are not car engines we are talking about here folks, premium does make a difference.

One other point to make: a few times I swore that I heard my engine ping on 87. I can't 100% prove it, but what a scary sound, let me tell you. It could easily be mistaken for normal V2 noises to the untrained ear. Once again, it was night and day on my bike, about a mile after filling up with 'real fuel' my engine smoothed out, the noises went away, and life was good again.

CentralCoaster

So how do you know it makes a difference? And is there any tangible facts to back it up, or just subjective observations and power of suggestion? The science says premium won't benefit you. So if you are trying to convince people otherwise, the burden of proof is yours.

And how (or why) are these fundamentally different than car engines? I think they're quite similar.

JamieDaugherty

They are similar in the sense that both have pistons, cams, cranks, etc. Motorcycle use a pentroof type combustion chamber which allows for higher compression. Do the math on the power output vs. displacement and you'll see that even a modest engine like the VTR is like a 600hp Corvette engine.... except that it revs higher. Motorcycle engines have proportionally high lift cams and lots of rpm, things car engines don't like.

So yes, they are similar but yet a lot different.

Take an objective look at the facts on what the VTR engine IS and make the choice for yourself. I think it's apparent that it's not an engine for regular ol' petrol.

You asked for fact, here are some facts based on my riding:

Miles per year = 4000 (max, usually more like 2000-3000)
Average mpg = 36
Gallons consumed per year = 111
Difference between 87 and 91+ = $0.20
Cost difference per year = $22.22

$20 per year. I mean come on, why would you not use premium?

mikstr

If I may. While I realise the VTR is a four-stroke, years ago, when the Ski-Doo MXZ700 twin cylinder two-stroke snowmobile came out (Rotax engine, 2000), the mfr called for 87 octane (this was an engine putting out 122 hp out of 699 cc). Dyno tests (same dyno, same day) showed that running 91 octane (as opposed to 87) resulted in a 2 hp loss (not major but significant nonetheless). Barring detonation issues (which I have never experienced), I am not certain I want to pay more money for less performance.

I also recall reading in one of the dirt bike rags (Dirt Bike or Motocross Action) they did a comparo of 87, 89 and 91 octane. The ran the bikes for some time on each type and tore the engines apart to look at the insides. They found the 91 resulted in residue on various parts, the best being the 89 octane. Not sure how relevant this still is but it made for an interesting read.

Last point. I recall from my time working in the petroleum industry that the profit margins for premium were MUCH higher (cost to produce was higher by 1.5-2 cents per litre but price at teh pump was 12 cents higher, the spread being.... profit). Any wonder they heavily promote premium as being the cure-all for engines? Food for thought.

fuzzuki

I'm pretty sure Honda recomends using 91.
I've tried them all and found no difference with octane.
So I still put regular.

fuzzuki

Just pulled out my owners manual.
They recomend 86 or higher.

khanawalt

Because there is no benefit to it? How about this: If it makes you feel better, and you think the bike runs better, you should do it. Me, I'd rather not spend a tiny bit more money on something unnecessary. In many posters' cases here, it's well worth the benefit, but I think the benefit is psychological, and well worth it for ya.

The only vehicles I have used anything other than regular in was merely to eliminate detonation. Three so far: an '82 Yamaha Seca Turbo with power-up kit and advanced timing, an '85 TPI Camaro, but only necessary in warm weather, and a '98 Jeep Grand Cherokee 5.9L that ALWAYS requires it for some unknown reason.

swordfish

if it was psychological, then why would we prefer a type of gas that costs more? we aren't doing ourselves any favors by saying the bike runs better on the expensive stuff. the gas companies aren't paying us. we have no reason to choose it, other than the fact that it makes a legitimate difference. if I was going to talk myself into prefering one or the other, wouldn't I talk myself into the one has a price advantage? I'd love it if the hawk ran better on the 87. I gave it a shot. I was rooting for the 87. now I'm assuming you weren't trying to be offensive when you said the benefit was psychological, but the fact is, you just questioned the objectivity of a good chunk of the people who posted about this. you're basically saying that the people who chose premium, some of which are the most educated and intellegent people I've ever spoken to, can't tell good gas from bad.are you serious? do we seem like children to you?"psychological" I like that. you want to dispute an opinion, ok, but you don't tell us "well you're all crazy. But that's ok, it works for you". can you guess what 2 word phrase springs to mind when presented with that mentality?let me know if you can't. no wait. don't. we've heard your opinion. now kindly take it and shove it somewhere we can't hear it. becuase you needed to insult several of us in order to defend it.

Tweety

And looking at this, I can clearly tell that you won't come to a conclusion... Why?!

Simple! TMFV! = To Many ******* Variables! Ok?! So now stop insulting each other please...

If we all where running bone stock VTR's of the showroom floor and had the exact same gas from the exact same company and THEN compared regular or premium or whatever we could possibly come to a conclusion...

But as it is most of us have mounted different exhausts, re-jetted and tuned our bikes... And obviously we have tuned them to the type of gas that we prefer... When we fill the tank up with premium and then adjust our bike to run perfect on that it will run less perfect on regular... Works the same the other way...

Also it's very well known that the quality of the gas varies, and the amount of stupid additives and type of them in said gas is just guesswork for all of us... The difference in the gas isn't big enough to cause detonation on a mostly stock engine... Only if you screw around with the innards you might cause that to be an issue...

So pick one and tune for that, and then be happy knowing that the bike runs well on it...

BTW Swordfish, unless you stick it on a dyno and get A/F readings that are 100% perfect I'd say your opinion on how your bike runs is about 50% science, 50% psychology, and 50% bad math's soo I would'nt call that an insult... Just facts...

fuzzuki

This is one of the reasons why my bike is "bone stock."

The VTR runs perfectly bone stock.
I like it that way. I don't need any more power for riding on the street.

Thumper

+1

Tweety

Yeah it does... If perfect means carb farts and stalling at the stoplights or if you happened to pull the clutch at highway speed... And other stupid nonsense that my bone stock engine did, regardless of the type of gas...

Not all of us live in an area that has the ideal elevation/temp/humidity so we adjust... Other than that it will not run perfectly... Simple as that... It's a carb'ed bike and it's slightly finicky so stock may not work for all occasions...

Then there is the matter of removing pair and such crap... again makes for adjustment... Add an after market exhaust and you again adjust...

I can go on making the list longer... So to you as well as others... If you wan't to make a blanket statement that implies running a completely stock unmodified and not adjusted engine, then you need to state that... Same for a highly modified engine... Blanket statements are just annoying...

Stevebis1

I was going to propose a dyno test 87 vs. 91/93. I'd paypal $20 to someone who is in a position to get a dyno pull done - and probably a dozen others would too.

But

Tweety makes perfect sense. Ayone who has jetted their bike has obviously done it for the fuel they typically buy. Even in "stock" setups there may be variability that we don't know. Finally there is DEFINITELY differences with the fuel we all buy - regional additives, summer/winter mix, ethanol %, brand formulation differences, etc
10 years ago my brother-in-law (a Honda automobile tech) showed me a Honda TSB that all but said don't use Mobil gas.
Point is, what would the dyno tell us? Just some more info we would all dispute.

Psychological or not I KNOW both my car and my bike (both honda engines) LIKE non ethanol gas. The car gets premium cause Acura calls for it, and the bike get regular - with an occasional tank of premium whenever I "feel" bad about feeding her cheap fuel.

khanawalt

Because you legitimately believe that it makes a difference. My wife thinks magnets on her wrist relieve pain, but I don't see how that makes sense. I don't think she's an idiot.

It's just that octane level increase is only justified by pre-ignition, and the difference in the way a bike runs would not be related to it in the absence of detonation.

If there are other variables like different additives and purity of fuel, that could explain why some are getting results, I suppose. I'm not buying it, literally and figuratively.

CentralCoaster

That's the sort of reasoning they use on their TV commercials for pecker-enhancement. "If it didn't work, then how could we afford to offer you such a deal?"

It becomes psychological when people feel the need to defend their ego for poor purchase decisions. It's the same reason people claim the "Tornado air intake" and "fuel magnets" work. They want to believe it works, because admitting otherwise would be to admit they were foolish for spending the money on it or buying into the BS that Shell tells you on their TV commercials.

If we look at the choices objectively and don't back ourselves into a corner defending them, then it's not a big deal to change our mind later.

Billzilla15