Wilsons Sandbox

On Wed, 19 Apr 2006 02:26:39 -0000 "st1100john" writes:

> Was reading some material today (I know dangerous) and came across > the > octane recommendation for the KLR. It stated 91 octane. I have > always > used 87. Never pinged or seemed down on power and I get about 40 > mpg > at highway speeds. What octane do most of y'all use?? > > Take care, > > John

<><><><><><> <><><><><><> John, I use 85 and sometimes go up to 87. I do most of my non touring riding at elevations between 3,200 and 6,800 feet. I don't lug the engine. Touring I sometimes get up to 11,000 feet if I recall correctly but that's only for short periods of time. But I like elevation for the riding and the views. At lower elevations I'd consider going to a higher octane fuel. I avoid fuel with ethanol as much as possible. Best, Jeff Saline ABC # 4412 South Dakota Airmarshal Airheads Beemer Club www.airheads.org The Beautiful Black Hills of South Dakota 75 R90/6, 03 KLR650, 79 R100RT

I read this in the manual, too. Here's my thoughts... Typically, engines with compression ratios of 9.3:1 or more benefit from higher octane fuels. The KLR is 9.5:1. Typically, if fuel octane is too low for a given compression ratio, the fuel prematurely and spontaneously ignites and the fuel explodes rather than burns. This can result in incomplete combustion which translates into power loss and/or potential engine damage/deposits. On very hot days going up hill, you might hear that occassional knock or ping or even dieseling in a lower RPM band - this is an example detonation. It can vary from a faint noise on light acceleration to a constant, deep hammering noise while driving at a constant speed. It's important to identify where the conditions have changed (sudden onset of noises) versus say an improperly tuned engine - which can also be the cause (e.g., lean fuel mixture, bad timing, etc.) Many have run 87 for the life of the bike without any octane related problems, but I think if you're running higher altitutes or heavy loads on hot days, you're best to run higher octane to reduce the risk of damage from detonation. At most, $.30 more per gallon and assuming a full 6 gallons, it's cheap insurance on those days you spare no mercy on your KLR. Without specifically testing and comparing a specific bike under static conditions (same load, route, humidity, altitude, pressure, temp...), it's hard to make a blanket statement that you'll get better fuel mileage. Sure there's more potential energy in premium fuel, but it's ultimately your compression ratio, tuning and ambient conditions that determine the results. As for me, I'm running 87 octane right up to the point I go vertical in the hot punishing desert or ride 2up with heavy gear. Then I buy the local premium blend and still enjoy the cheap prices. [Despite recent rise, it's still much cheaper and easier than getting it out of the ground and refining it yourself! What's really interesting is looking at a quart of Valvoline oil at any autoparts store...$2.50/qt (that's $10/gal). My guess is unleaded fuel will hit $5+/gal for any grade within 10 years...]

--- In DSN_KLR650@yahoogroups.com, Jeff Saline wrote: > > On Wed, 19 Apr 2006 02:26:39 -0000 "st1100john" > writes: > > Was reading some material today (I know dangerous) and came across > > the > > octane recommendation for the KLR. It stated 91 octane. I have > > always > > used 87. Never pinged or seemed down on power and I get about 40 > > mpg > > at highway speeds. What octane do most of y'all use?? > > > > Take care, > > > > John > <><><><><><> > <><><><><><> > > John, > > I use 85 and sometimes go up to 87. I do most of my non touring riding > at elevations between 3,200 and 6,800 feet. I don't lug the engine. > Touring I sometimes get up to 11,000 feet if I recall correctly but > that's only for short periods of time. But I like elevation for the > riding and the views. At lower elevations I'd consider going to a higher > octane fuel. I avoid fuel with ethanol as much as possible. > > Best, > > Jeff Saline > ABC # 4412 South Dakota Airmarshal > Airheads Beemer Club www.airheads.org > The Beautiful Black Hills of South Dakota > 75 R90/6, 03 KLR650, 79 R100RT >

Hi John, Would you care to share with us this 'source' that suggest 91 octane is required? Was it KHI or fu-bar the web-slinger? I don't believe 91 octane is what the manual suggests (my manual is 117 miles from here....) revmaaatin.

--- In DSN_KLR650@yahoogroups.com, "st1100john" wrote: > > Was reading some material today (I know dangerous) and came across the > octane recommendation for the KLR. It stated 91 octane. I have always > used 87. Never pinged or seemed down on power and I get about 40 mpg > at highway speeds. What octane do most of y'all use?? > > Take care, > > John >

It's a rather poor topic to argue as there are pitfalls in either direction - to premium or not to premium. But scientifically, higher octane fuel contains more potential energy but requires the higher heat generated by higher compression ratio engines to properly condition the fuel to release it. Higher octane fuel is slightly denser than lower-octane, meaning there's a little more energy in a gallon. Good night all. - Brian

--- In DSN_KLR650@yahoogroups.com, jokerloco9@... wrote: > > I agree with what you said, except with what you said about "premium fuel > has more potential energy". It doesn't. It has less. The most energy dense > part of what we call "gas" is the base gas, I think called white gas. It has > an octane of about 50 by memory. In order to raise octane, we add stuff to > it. These chemicals do not contain near the same energy as gasoline. So when > they are added, they are displacing a like amount of white gas, resulting in > total lower energy value per unit volume, as the octane rises. > > I only bring this up because many people think they will get better mileage > with premium. You will get less. A small amount, but it will be correct > answer for Wheel of Fortune > > It only works that way if engine is designed to work on premium, and you run > it on regular. Many modern engines have things like knock sensors that will > retard timing, decreasing efficiency, but saving your motor, if you have bad > or lower octane gas. Then they will of course operate better on premium. > But an engine designed for regular will not run any better on premium, it will > actually have lower mpg. > > Jeff A20 I'm tired and don't want to explain it any better than that right > now. sorry. > > > [Non-text portions of this message have been removed] >

It was from an article in Motorcycle Consumer News about the KLR. This months issue. Like I said I've always used 87 and never a problem, so just had to wonder where they got their information. John

--- In DSN_KLR650@yahoogroups.com, "revmaaatin" wrote: > > Hi John, > Would you care to share with us this 'source' that suggest 91 octane > is required? Was it KHI or fu-bar the web-slinger? I don't believe 91 > octane is what the manual suggests (my manual is 117 miles from > here....) > > revmaaatin. > > --- In DSN_KLR650@yahoogroups.com, "st1100john" wrote: > > > > Was reading some material today (I know dangerous) and came across > the > > octane recommendation for the KLR. It stated 91 octane. I have > always > > used 87. Never pinged or seemed down on power and I get about 40 > mpg > > at highway speeds. What octane do most of y'all use?? > > > > Take care, > > > > John > > >

--- In DSN_KLR650@yahoogroups.com, "traderpro2003" wrote:

>

if you're running higher altitutes or heavy

> loads on hot days, you're best to run higher octane to reduce the > risk of damage from detonation.

At higher altitudes, you can get by with lower octane.

I think it has more to do with the quality of the fuel and the additives that are put in it such as MTBE or ethanol. I live at low elevation in the Midwest and usually run 87 octane which is 10% ethanol and has always made my bikes ping under heavy load. The left over 85 octane I hauled back from Colorado last fall ran perfectly here with no pinging. I could pay extra and run premium or go to Amoco which here locally is not 10% ethanol but I am cheap and my KLR's runs well enough and average 50 MPG.Ken

--- In DSN_KLR650@yahoogroups.com, "st1100john" wrote: > > Was reading some material today (I know dangerous) and came across the > octane recommendation for the KLR. It stated 91 octane. I have always > used 87. Never pinged or seemed down on power and I get about 40 mpg > at highway speeds. What octane do most of y'all use?? > > Take care, > > John >