MACDADDYBMWR1200RT
The Kansas Tornado
Hey I've got a good question for Y'all, if BMW recommends 91 or better octane for the R1200RT, could you run 94 octane Ethanol 85 in it?
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Fuel Question
- Thread starter MACDADDYBMWR1200RT
- Start date
Actually, BMW recommends 93 pump octane. So let us know how your RT runs on E85.
deilenberger
A bozo on the bus
I wouldn't do that. The fuel system wasn't designed with E85 in mind.. It might run - for a while (and where you you find 94 octane E85?)
MACDADDYBMWR1200RT
The Kansas Tornado
In Kansas at the pump, the octane label says 94. What's interesting is that the manual is unclear as to what you can run in your bike. Even though it recommends 91 or better octane, it states that you can run other grades with different results, or something like that ( I don't have manual here to look at.)
greenwald
New member
Tech Session Fuel Advice
Recently attended a Tech Session at my BMW dealer for oilheads. Subject of fuel was discussed, and basically the advice was as follows:
Avoid any ethanol fuel greater than 10% in oilheads (2005 or newer) and use premium fuel (octane ratings may vary but premium fuel recommended).
While the engine computer/oxygen sensors can 'compensate' for medium-grade fuels with lower octane ratings, you've bought the 'swiss watch' of motorcycles - don't get your batteries for it at the Dollar Store.
Ride Alert!
Recently attended a Tech Session at my BMW dealer for oilheads. Subject of fuel was discussed, and basically the advice was as follows:
Avoid any ethanol fuel greater than 10% in oilheads (2005 or newer) and use premium fuel (octane ratings may vary but premium fuel recommended).
While the engine computer/oxygen sensors can 'compensate' for medium-grade fuels with lower octane ratings, you've bought the 'swiss watch' of motorcycles - don't get your batteries for it at the Dollar Store.
Ride Alert!
R
RIDERR1150GSADV
Guest
IIRC most 'older' BMW's are designed for use of 89 octane gas with perhaps the new K engines for higher rated octane gas.
I have run all my bikes , boats and cages on 87 or 89 octane and never had any issues. I also rarely redline the engines either or expect maximum power from them running this type of fuel. Spending extra $$ on higher octane is a waste of money if the engine is not designed for it. If you take it easy on the engine(s), you can get away with a lower octane fuel. If you do hear pinging than you need to step it up a notch from what you have been using. Higher octane does NOT provide more power. It is a anti-knock index not a HP index. Just my 0.02 cts. YMMV.
I have run all my bikes , boats and cages on 87 or 89 octane and never had any issues. I also rarely redline the engines either or expect maximum power from them running this type of fuel. Spending extra $$ on higher octane is a waste of money if the engine is not designed for it. If you take it easy on the engine(s), you can get away with a lower octane fuel. If you do hear pinging than you need to step it up a notch from what you have been using. Higher octane does NOT provide more power. It is a anti-knock index not a HP index. Just my 0.02 cts. YMMV.
My 1976 R75/6 was designed for the 95 pump octane available in those days. It would detonate badly above 4,000 rpm on 92 octane which is why folks compensated with thicker base gaskets or dual plugged heads in the early 1980's when U.S. octane began to decline.
And yes, higher octane does provide more power if the engine is designed for it. The hexheads are and use a knock sensor to adjust the timing for lower octane gas, reducing both power and fuel mileage. The owner's manual for my '06 RT clearly claims 110 hp when using 98 RON octane fuel - 98 RON being equivalent to 93 (R+M)/2. It also specs 101 hp when using 91 RON (equal to our 87 pump.
njnear
NJN EAR
12:1 pistons.... I think 91 is a little low even though the manual says it's OK. I avoid putting anything in it that's less. Yes the computer will keep it from spark knocking, but I wouldn't chance it on a regular basis.
As for the E 85, the seals/gaskets etc. won't handle all the alcohol (as stated above). E 85 is a different density than gasoline, so your metering system (not carburation) will likely not function properly. On top of that you'll get about 2/3 of the BTU's of gasoline and performance would suffer (including gas mileage).
As for the E 85, the seals/gaskets etc. won't handle all the alcohol (as stated above). E 85 is a different density than gasoline, so your metering system (not carburation) will likely not function properly. On top of that you'll get about 2/3 of the BTU's of gasoline and performance would suffer (including gas mileage).
S
screamineagle
Guest
E-85 fuel
I am not an expert on fuel but what I have heard is the E85 fuel is much less efficient so that even though it is cheaper per gallon, when you do the calculations it cost the same per mile as galoline. If that is true (I don't know) why use it.
I am not an expert on fuel but what I have heard is the E85 fuel is much less efficient so that even though it is cheaper per gallon, when you do the calculations it cost the same per mile as galoline. If that is true (I don't know) why use it.
T
thartman
Guest
91 vs 93 octane
I sure notice it. I get 250 miles on a tank full of 93 octane but less than 170 miles if I have to use a lower octane. I do run at between 4,000 rpm and 5,000 rpm so maybe that hurts me. I was running on empty yesterday and filled it up with 91 octane then at half a tank topped off with 92 octane the highest I could find. Finally found a station with 93 and topped it off again. I ended up getting 164 miles on that tank before my "42 miles to go" warning came on.
I can repeat it every time, which I try not to do but it is hard to find 93 octane so I get to test it more than I like.
I sure notice it. I get 250 miles on a tank full of 93 octane but less than 170 miles if I have to use a lower octane. I do run at between 4,000 rpm and 5,000 rpm so maybe that hurts me. I was running on empty yesterday and filled it up with 91 octane then at half a tank topped off with 92 octane the highest I could find. Finally found a station with 93 and topped it off again. I ended up getting 164 miles on that tank before my "42 miles to go" warning came on.
I can repeat it every time, which I try not to do but it is hard to find 93 octane so I get to test it more than I like.
cjack
K Bikes Complex by Choice
NO. BMW specifically said (in some SB that I recall) they will not be responsible for faults caused by E85 and recommends a maximum of 10% Ethenol.
grafikfeat
New member
E85 eats gaskets, gasket sealants and rubber.
I ride a 2002 R1200c and run 87 octane. When I was using 89 and above I got 37-40 mpg. I went to 87 it went up to 43-48 and even broke the 50 mpg mark. It won't happen on one tank so run about three and you will see a change. If you get pinging go back to what you were running. But there is NO need to run hi-test. Waste of money.
But for me... I'll put that nickel in MY pocket before I give it to the rat bastard oil companies.
I ride a 2002 R1200c and run 87 octane. When I was using 89 and above I got 37-40 mpg. I went to 87 it went up to 43-48 and even broke the 50 mpg mark. It won't happen on one tank so run about three and you will see a change. If you get pinging go back to what you were running. But there is NO need to run hi-test. Waste of money.
But for me... I'll put that nickel in MY pocket before I give it to the rat bastard oil companies.
+1
I would not run any ethanol unless absoluty necessary.
If you're in an area of the country where you have to use it, I would start planning on having the rubber seals and gaskets replaced.
Easy
C
cheesewhiz
Guest
HATE THE E-85!!!!!
Your local Quik Trip has Top Tier premium with NO ETHANOL.
I'm not sure, but I think the mandate for ethanol use is for regular grade with no demands for it's use in the higher grade fuels.
The law states that the ethanol "mix" fuel shall be clearly marked on the pump. Keep your eyes open for the clean stuff.
Hope this helps.
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Octane vs Mileage/power
I have the unique opportunity to travel 600 miles each weekend over the same route. I have been doing it for over 2.5 years and been able to really measure some of these things (you really reach for things to do after the first year or so..). I had an '04 Rt that got 48-49 MPG (dino oil, 93 octane). I changed to 89 Octane and it went down to 43-44mpg. it was a $.10 savings for the lower octane, less than 2.5% (gas was 2.60-2.80 or so then. remember the good ole days?). Since it was a 10% increase in mileage, I stayed with the higher octane. I changed to synthetic oil, got another 10% increase in Mileage. I was consistently getting 52-53 mpg, measure/averaged over 10 tank batches. I have an '07 RT now and am seeing similar results, although so far my mileage is looking like 55-56 on Premium/dino oil. You may get different results but that's what I got.
I have the unique opportunity to travel 600 miles each weekend over the same route. I have been doing it for over 2.5 years and been able to really measure some of these things (you really reach for things to do after the first year or so..). I had an '04 Rt that got 48-49 MPG (dino oil, 93 octane). I changed to 89 Octane and it went down to 43-44mpg. it was a $.10 savings for the lower octane, less than 2.5% (gas was 2.60-2.80 or so then. remember the good ole days?). Since it was a 10% increase in mileage, I stayed with the higher octane. I changed to synthetic oil, got another 10% increase in Mileage. I was consistently getting 52-53 mpg, measure/averaged over 10 tank batches. I have an '07 RT now and am seeing similar results, although so far my mileage is looking like 55-56 on Premium/dino oil. You may get different results but that's what I got.
ANDYVH
New member
The problem with the "rubber" components is the water in ethanol in the high temperature environment of an engine literally attack the rubber and causes it to age quickly and crack. By high temperature I mean anything above 140 degrees and up to the boiling point of water.
There is no true "rubber" on our bikes. It is a synthetic rubber like Neoprene, Nitrile, EPDM or other blended synthetic rubber. Nitrile, Buna-N (Viton) are the most common synthetic rubber materials for seals such as o-rings. Water at temperatures above 140 degrees F is actually very nasty on Nitrile seals in constant exposure to water in those conditions. Vehicles with fuel systems set up for E85 use silicon, EPDM, or blended Nitrile/EPDM seals to stand up to the high temp water component of ethanol fuels.
But also given that E85 has less potential energy per gallon than does gasoline, we gain nothing using E85 because we get less performance and mileage for the slight savings at the pump. So you end up buying more of it to make up the difference.
There is no true "rubber" on our bikes. It is a synthetic rubber like Neoprene, Nitrile, EPDM or other blended synthetic rubber. Nitrile, Buna-N (Viton) are the most common synthetic rubber materials for seals such as o-rings. Water at temperatures above 140 degrees F is actually very nasty on Nitrile seals in constant exposure to water in those conditions. Vehicles with fuel systems set up for E85 use silicon, EPDM, or blended Nitrile/EPDM seals to stand up to the high temp water component of ethanol fuels.
But also given that E85 has less potential energy per gallon than does gasoline, we gain nothing using E85 because we get less performance and mileage for the slight savings at the pump. So you end up buying more of it to make up the difference.
BeemerMike
Republic of Texas
Octane-Power-Ethanol
Wow, a lot of interrelated ideas floating around here!
Just a few "basics" to keep in mind as this thread progresses:
1. Gasoline blending is a VERY complex process, involving the mixing and balancing of a large number of different hydrocarbon compounds and additives . . . each with different properties, benefits, and detriments . . . to achieve the desired product result. This makes it more difficult to directly compare one gasoline to another, especially if you switch between brands, because you cannot be sure of the other differences besides octane rating that may be affecting your comparison (e.g., the exact ethanol content).
2. Octane and Power (energy) are NOT the same thing. In fact, I believe that the higher octane gasolines actually have a little LESS energy per gallon than the lower octane gasolines, due to the different mixes of hydrocarbon compounds. Hydrocarbon compounds with a higher octane rating do not necessarily have a higher energy content/density.
3. MTBE (methyl-tertiary-butyl-ether) and ethanol (what replaced MTBE) are BOTH octane boosters and oxygenates. Adding ethanol to gasoline INCREASES the octane rating (although it lowers the energy content - see #4 below).
4. Ethanol has LESS energy per gallon than does the base gasoline blend. The more ethanol you add to gasoline, the LESS energy per gallon you will have. E85 has less energy per gallon than does E10 (90% gasoline-10% ethanol). Therefore, in general, you will travel farther on a gallon of E10 than you will on a gallon of E85 (i.e., more MPG).
5. Some engines (with knock sensors and sophisticated engine management systems) can take advantage of a higher octane gasoline to INCREASE the EFFICIENCY of using the available energy in the gasoline (e.g., timing advance), with the result that you will get more HP and MPG with a higher octane gasoline than with a lower octane gasoline. Absent those sophisticated systems (or you manually making adjustments to your engine), there should be no advantage to using a higher octane gasoline than what is required to avoid "knocking" (assuming the gasolines are the same in all other respects, which is not always easy to know). This is why "high performance" engines need higher octane gasoline . . . not because the gasoline has more energy, but because the octane is needed to avoid knocking with the more aggressive characteristics of the engine (higher compression ratio, advanced timing, etc.).
6. Ethanol can attack certain kinds of "rubber" in the fuel system AND ethanol absorbs water - both directionally bad for your engine. Engines certified for E85 use different rubber compounds that can stand up to the ethanol content than can other engines. The engine manufacture specifies what ethanol content the engine can use.
OK . . . go!
Wow, a lot of interrelated ideas floating around here!
Just a few "basics" to keep in mind as this thread progresses:
1. Gasoline blending is a VERY complex process, involving the mixing and balancing of a large number of different hydrocarbon compounds and additives . . . each with different properties, benefits, and detriments . . . to achieve the desired product result. This makes it more difficult to directly compare one gasoline to another, especially if you switch between brands, because you cannot be sure of the other differences besides octane rating that may be affecting your comparison (e.g., the exact ethanol content).
2. Octane and Power (energy) are NOT the same thing. In fact, I believe that the higher octane gasolines actually have a little LESS energy per gallon than the lower octane gasolines, due to the different mixes of hydrocarbon compounds. Hydrocarbon compounds with a higher octane rating do not necessarily have a higher energy content/density.
3. MTBE (methyl-tertiary-butyl-ether) and ethanol (what replaced MTBE) are BOTH octane boosters and oxygenates. Adding ethanol to gasoline INCREASES the octane rating (although it lowers the energy content - see #4 below).
4. Ethanol has LESS energy per gallon than does the base gasoline blend. The more ethanol you add to gasoline, the LESS energy per gallon you will have. E85 has less energy per gallon than does E10 (90% gasoline-10% ethanol). Therefore, in general, you will travel farther on a gallon of E10 than you will on a gallon of E85 (i.e., more MPG).
5. Some engines (with knock sensors and sophisticated engine management systems) can take advantage of a higher octane gasoline to INCREASE the EFFICIENCY of using the available energy in the gasoline (e.g., timing advance), with the result that you will get more HP and MPG with a higher octane gasoline than with a lower octane gasoline. Absent those sophisticated systems (or you manually making adjustments to your engine), there should be no advantage to using a higher octane gasoline than what is required to avoid "knocking" (assuming the gasolines are the same in all other respects, which is not always easy to know). This is why "high performance" engines need higher octane gasoline . . . not because the gasoline has more energy, but because the octane is needed to avoid knocking with the more aggressive characteristics of the engine (higher compression ratio, advanced timing, etc.).
6. Ethanol can attack certain kinds of "rubber" in the fuel system AND ethanol absorbs water - both directionally bad for your engine. Engines certified for E85 use different rubber compounds that can stand up to the ethanol content than can other engines. The engine manufacture specifies what ethanol content the engine can use.
OK . . . go!
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The_Veg
D'OH!
HATE THE E-85!!!!!
Your local Quik Trip has Top Tier premium with NO ETHANOL.
I'm not sure, but I think the mandate for ethanol use is for regular grade with no demands for it's use in the higher grade fuels.
The law states that the ethanol "mix" fuel shall be clearly marked on the pump. Keep your eyes open for the clean stuff.
Hope this helps.
Down in my neck of the woods there is one big sticker per pump (not per grade) indicating that "fuel may contain up to 10% ethanol," so I generally assume that I'm getting 10% in all grades. MPG results seem to bear this out.
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