Fuel Question

[LostTexan]

I just got a new 2008 K1200GT. My owners manual says to use "98 ROZ/RON Super Unleaded or 95 ROZ/RON Super unleaded (fuel type can be used with reduced performance and consumption)". I recently found a link to Minnesota stations that sell non-oxygenated (ethanol-free) fuel. Should I use the non-oxegenated fuel?
http://www.msra.com/NonOxygenatedFue...2008.27.08.pdf

[Vagabird]

I'd go with the best fuel you can find. My bikes run fine on almost anything, but I've noticed I don't get the mileage if I use regular or gas with ethanol. Some places that's all you can get, but if you can get 93 or 94 octane with no ethanol, it's worth the extra expense.

[Zygmund]

Lost Texan,
I keep that list from the MSRA in the tank bag, nice to have when you are out and about and want non ethanol fuel.

[bikerfish1100]

I'd go with the best fuel you can find.

nope. you run the lowest that the bike will burn without pinging (detonation), anything beynd that is a waste of money. period. that may be 93, or it might be 89. i'd start with a tank of the best stuff, then at about a half tank down, refill with the next lower grade. keep experimenting till you find what works, even under hard demands (uphill, loaded, hard acceleration).

[LostTexan]

Thanks for all the input. Appreciate the coaching.

[bobbobtar]

Lost Texan,
The non-oxygenated fuel is only available in premium( 91 octane ) in Minnesota,It's the only fuel I use in the RT,lawn mower, wood splitter and chain saw.

[Vagabird]

nope. you run the lowest that the bike will burn without pinging (detonation), anything beynd that is a waste of money. period. that may be 93, or it might be 89. i'd start with a tank of the best stuff, then at about a half tank down, refill with the next lower grade. keep experimenting till you find what works, even under hard demands (uphill, loaded, hard acceleration).

I've never experienced pinging on either R12, regardless of what I put in. But I get 47-51 mpg on my RT if I use 91 octane and 39-43 if I use 87 octane. It doesn't seem to me like I'm saving any money with the cheaper gas.

[TexanRT]

I've never experienced pinging on either R12, regardless of what I put in. But I get 47-51 mpg on my RT if I use 91 octane and 39-43 if I use 87 octane. It doesn't seem to me like I'm saving any money with the cheaper gas.

What about additives? In addition to fuel-economy and ping-reducing qualities of super unleaded fuels, don't they contain additives helpful in maintaining the operating efficiency of the fuel delivery system and the cleanliness of the combustion chamber? And -- can your dealer tell if you've been burning lower octane fuel? Like the question on oil & oil filters, does this have implications for warranty service?

I've seen pictures of valves taken out of motors burning regular and premium fuels and could see the difference -- but are those claims real? If you've taken apart a motor -- did you know whether the motor was run on regular or premium fuel?

[Vagabird]

Now you're getting out of the my area of experience. I think that premium and regular will have the same additives. Gas from the same refinery sent to 7-Eleven and sent to an Exxon station will have different additives, depending on the specifications of the chain. Whether that makes any difference, I don't know.

I do know that my bikes will not pull nearly as well when running regular as they do when running premium. With modern computer-driven fuel injection, pinging is rare. But the manufacturer sets it all up to run on a certain octane, and the engine will not be as efficient on less. Whether that results in sooty valves, I don't know.

Meanwhile, I can burn anything in my car and it doesn't seem to make any difference, so I just get the cheapest gas for that. I buy brand-name premium for my bikes because they seem to run better on it. After all, a car is just transportation, but a bike is Life.

[TexanRT]

After all, a car is just transportation, but a bike is Life.

+1 on that. Thanks.

[BUDDINGGEEZER]

Here is how the octane rating of gasoline is measured:

Measurement methods

The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane.

There is another type of octane rating, called Motor Octane Number (MON) or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the "headline" octane rating, shown on the pump, is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, the octane rating shown in the United States is 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, is 91ÔÇô92 in Europe. However most European pumps deliver 95 (RON) as "unleaded", equivalent to 90ÔÇô91 US (R+M)/2, and some even deliver 98 (RON), 100 (RON), or 102 (RON).[2]

Most modern computer controlled fuel injection engines which include late model BMW motorcycles have a spark knock sensor, which retards the ignition timing when a knock is detected. This feature allows a lower octane fuel to be run and the engine not knock(ping). The lower ignition timing results in less engine power and that's why the gas mileage drops.

Ralph Sims

[TexanRT]

Most modern computer controlled fuel injection engines which include late model BMW motorcycles have a spark knock sensor, which retards the ignition timing when a knock is detected. This feature allows a lower octane fuel to be run and the engine not knock(ping). The lower ignition timing results in less engine power and that's why the gas mileage drops.

Could that de-tuned condition result in dirtier combustion and the dirtier valves we see the photos of in the advertisements?

[BUDDINGGEEZER]

Could that de-tuned condition result in dirtier combustion and the dirtier valves we see the photos of in the advertisements?

I don't think so. The dirty valves in the advertisements are more a product of fuel with less detergents if they haven't tuned the engine to run extra rich.

Iso octane causes fuel to burn slower. The higher compression an engine has the harder the fuel charge is squeezed in the cylinder. this harder squeeze makes the fuel easier to ignite causing the lower octane fuel to ignite to soon trying to drive the piston back down while it's still on the compression stroke. This is the knocking or pinging sound. The knock sensor delays the spark plug firing a few degrees to compensate. The fuel charge should still fully ignite and burn clean.

Now with engines designed to run on the lower octane fuel (regular 87 AKI) running the higher octane fuel can cause the engine to carbon up. Why? The engine is designed to completely burn the faster burning lower octane charge. The higher octane slower burning fuel may not completely burn leaving carbon deposits. It also may not completely burn and unburned fuel can be exhausted from the engine reducing power. I had a K100Lt designed for 91RON (87 AKI) and I got less gas mileage on premium fuel.

Higher octane doesn't mean a more powerful fuel, just a slower longer burning fuel.

The old adage of running the lowest octane fuel that doesn't cause the engine to knock is true on engines that do not have knock sensors. I would sugest running the grade fuel that the manufacturer recommends.

Non alcohol fuel is better than alcohol fuel. It's getting hard to find, and why would you want 10% of your fuel to have less explosive power?

Ralph Sims

[TexanRT]

Thanks for that explanation. Looks like you'd need a significant difference between super and regular fuel prices to offset the effect of the lost mileage.

[ragtoplvr]

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Since the minimum additive performance standards were first established by EPA in 1995, most gasoline marketers have actually reduced the concentration level of detergent additive in their gasoline by up to 50%. As a result, the ability of a vehicle to maintain stringent Tier 2 emission standards have been hampered, leading to engine deposits which can have a big impact on in-use emissions and driver satisfaction.

Linky

http://www.toptiergas.com/

I try to use only stations that are on the list. There is seldom a price difference.

Rod