[Jimding]

Can't figure out how my buddy on an F650GS beat me by 10 MPG on EVERY TANK.

Pretty sure the BMW runs a closed-loop fuel injection setup, where the FI knows, many times per second, just what the mixture is, and adjusts mixture, and perhaps timing, accordingly. In addition, BMW is perhaps better at combustion-chamber design, yielding better efficiency. On the other hand, we're stuck with open-loop injection and a fixed timing map (probably pretty conservative) so we don't get quite as much useful energy per gallon.
Edit: - Forgot to add that the BMW is probably putting out a larger percentage of it's maximum power (than a Vee, anyway) in regular use, which is a more efficient mode of power generation. Probably very little difference in the power requirements of a Vee and a Wee running at the same speed (excluding internal engine friction and pumping loss from the more restricted intake, likely to be quite a bit less than the aero drag), but a Wee will get better mileage for that same reason.

 

[DBuck12]

I can't imagine that BMW would be better at combustion chamber design. There is simply no reason to assume this.

 

[rconti]

Edit: - Forgot to add that the BMW is probably putting out a larger percentage of it's maximum power (than a Vee, anyway) in regular use, which is a more efficient mode of power generation. Probably very little difference in the power requirements of a Vee and a Wee running at the same speed (excluding internal engine friction and pumping loss from the more restricted intake, likely to be quite a bit less than the aero drag), but a Wee will get better mileage for that same reason.

Over 9000 miles, comparing my 07 Wee with my buddy's 2010 F650GS, he consistently got at least 5mpg better per tank, every tank, than I did. He had boxer and larger cases than me, and his cargo was heavier than mine was. However, he had a small windshield with holes in it, where I have my CalSci medium that pushes a lot more wind.

Larger % of max power is backwards, I think. I found that, when cruising at moderate speeds, my Wee did WAY better than my buddy's VFR800. However, when the speeds ramped up, and I was using LOTS of wide-open throttle (passing cars, sustaining high speeds, etc), my mileage plummeted to the point where I was getting WORSE mileage than the viffer.

ymmv

 

[30416]

never see 40

It amazes me that people get 40+ MPG. I never see anything over 38MPG HW and 34MPG in town.

 

[Notabiker]

Again not sure how much the engine is different but I have a TL1000R in vintage 1999 yellow. Got 51 mpg cruising about 40 miles at 55mph with a burst to 130 and another to 155 running premium fuel as it's required. Normally it gets in the low 40's riding around the city. Have a Yosh full rs3 system and remapped with a Yoshbox, K&N filter with the dampers in the airbox lid removed and the PAIR system removed as well... Think it's how you are riding that mostly affects the MPG, that and wind resistance!

 

[Senderofan]

I think the difference in engine size might have something to do with the difference infuel economy as well. My buddy has a G 650 GS...which is the thumper of the line. We went on a 700-800 weekend cruise. He got 68-72 mpg...while I got 46-47 mpg driving similarly.

I'm not at all disappointed...got extra power for passing and more comfort. just my 2 cents.

Wayne

 

[Jimding]

Then again

I can't imagine that BMW would be better at combustion chamber design. There is simply no reason to assume this.

Looking at their current sport bikes (not to mention their Formula One engines) I think it is safe to say the BMW have considerable expertise in combustion chamber design, judging by the compression ratios they can get away with on regular gas. By comparison, I suspect our bikes (though they have their advantages)(and the inability or unwillingness of Suzuki to make significant changes to the bikes over the years) have a 'good-enough' design. And with open loop injection and a fairly primitive ignition setup, highly conservative. Meaning the engines, while reliable under a wide range of fuel quality (something BMW's generally need dealer adjustments to accomplish), do not extract maximum energy from each gallon of gas. And it is generally true that engines are most efficient (maximum HP/gallon) when they are running at a large percentage of their maximum output (relatively unthrottled). While this can be somewhat overcome with closed-loop injection, efficient combustion chamber design (high compression ratio, mostly), and adaptable ignition curves, we don't seem to have the benefit of those advantages. Not racking on the Vee (heck, I thinks it is the most fun bike I've ridden) bit it does have its shortcomings, like the drive train resonance/FI interplay (chudder) that Suzuki has never adequately addressed. If you want better mileage, get a bike with a smaller engine and run it harder.

 

[richw]

Blowing smoke but way back when Suzuki took over the power market with their 4 valve twin swirl cylinder now standard on everything.

This level of performance is voodoo. Take the TLR pseudo race motor and throwing in a tractor cam was bound to have short comings.

Ride the beotch


Note you can raise it like 1 to 2 MPG by running 1:75 oil in the gas

10000 miles at 40 MPG = 250 Gallons X 3.75 $/gal = 937.50

10000 50 mpg 200 x 3.75 = $ 750

so 187.50 difference for the year

8 month riding season here or 34 weeks

so the price of a Latte a week

 

[DBuck12]

Looking at their current sport bikes (not to mention their Formula One engines) I think it is safe to say the BMW have considerable expertise in combustion chamber design, judging by the compression ratios they can get away with on regular gas. By comparison, I suspect our bikes (though they have their advantages)(and the inability or unwillingness of Suzuki to make significant changes to the bikes over the years) have a 'good-enough' design. And with open loop injection and a fairly primitive ignition setup, highly conservative. Meaning the engines, while reliable under a wide range of fuel quality (something BMW's generally need dealer adjustments to accomplish), do not extract maximum energy from each gallon of gas. And it is generally true that engines are most efficient (maximum HP/gallon) when they are running at a large percentage of their maximum output (relatively unthrottled). While this can be somewhat overcome with closed-loop injection, efficient combustion chamber design (high compression ratio, mostly), and adaptable ignition curves, we don't seem to have the benefit of those advantages. Not racking on the Vee (heck, I thinks it is the most fun bike I've ridden) bit it does have its shortcomings, like the drive train resonance/FI interplay (chudder) that Suzuki has never adequately addressed. If you want better mileage, get a bike with a smaller engine and run it harder.

I'm aware of BMW's considerable expertise in combustion chamber design I just don't think it exceeds that of Suzuki engineers. I'm sure you know that higher compression is simply a matter of making a combustion chamber of smaller volume. As far as BMW's current sport bike power advantage I think most of this is the result of choosing a more radically over square design allowing for a higher RPM power range. I think there are very few 'secrets' when it comes to modern high performance four valve combustion chamber design.

 

[Phodius]

try using 91 or better octane fuel if youre not already doing so. i get a couple more mpg w/91 vs 87.

Octane, Oil, Tires, Sex, Religion, Politics and Education -- all subjects GUARANTEED to turn up the heat of any discussion into which they are introduced...every time. :yesnod:

 

[biggyfries]

On my DL1000 I don't baby it too much but I always get pretty good economy and occasionally crack 50mpg. I have a 16t front sprocket and the stock rear sprocket. At hiway speeds (65mph) I rarely have to downshift to pass. At my happy cruise speed the tach reads just around 4000, and it seems to get the same mpg's if you run a little faster (4300rpm). If you're cruising at 5000rpm you're going fast enough to endanger your license, and fuel economy starts to decline. The bike is happy as can be at 5000rpm but you have to decide if its worth it. If the pavement is curvy, then to hell with it--let er rip, and to heck with the mileage IMHO.
Another thing that helps economy is to choose non-ethanol gas if you can. Where I live there is none, but in the next state over, (ID) there is some non-ethanol gas available. MPG's come up a bit on straight gasoline. That's how I hit 50mpg a few times.

 

[Maco]

I normally get 260KM to 280KM on a tank riding in the mountians of B.C.
Last ride I was on I needed to get home so I took the high mountian Coquihalla Freeway that climbs to 1244 meters(4081 feet). When I started on the Coquihalla I had 80KM on the trip meter and 110KM later the fuel light was flashing. At a constant 160KPH climbing in the mountians the fuel mileage really drops. I have adusted the FI with the Yosh box and would not trade the way it runs for more mileage.

 

[crager34]

Recent 600+ mile trips to OH and back to TN I was at 45 & 46 mpg on the highway. I am 5'10" and 200 lbs, ran average of 4000 rpms and use 87 octane.

I am pleased.

 

[Saito]

Mine is doing 26mpg riding at 160km/h. I'm prety sure that's something wrong. :thumbdown:

 

[cvbruce]

4 years in, this is a detailed update on my DL1000 mileage. What you're seeing is a rolling 4-tank average fuel economy. The peaks, marked with arrows, are the beginning of each season ('08, '09, etc.). I bought it used in 2007. It now has about 70,000 km. I have only missed about three recorded fill-ups. Other peaks in the curve are when I was riding 2-up, with luggage, typically at either 70 km/hr on back roads or 120 km/hr on the highway. The really big peak was a run to Gaspe, 2-up, at about 130 km/hr, into the wind, up and down big, big hills.

I am gentle on the throttle and it's running stock gearing. I put in Regular (when in Canada...where I am) and Premium when I'm in the U.S. Aside: U.S. ethanol fuels suck. I get more backfiring and throttle stumbling.

What you see is a line of the linear version of the whole curve, from about 5.4 to 5.6 L/100 km. That means that the "average" fuel economy over the four years has been about 5.5 L/100 km. That's 42.8 US mpg. The best, 4-tank average, came out to about 5.1 L/100 km...46 US mpg.

Consequently, I get about 360 km into a tank when the gas light is REALLY hard to ignore...but it usually only needs about 19 L, then. Theoretically, I should be getting about 420 km to DRY. I'm not willing to find out. ;-)

 

[marshallnoise]

Mine is doing 26mpg riding at 160km/h. I'm prety sure that's something wrong. :thumbdown:

I am in the sameish boat. I am running low 30s and a best of 35 on the highway. I have 17/45 gearing though and been yoshed.

Personally, I think I over-yoshed my bike. :thumbdown:

 

[richw]

Have you had the valves done as in the cam came out ?

 

[danketchpel]

I put in Regular (when in Canada...where I am) and Premium when I'm in the U.S. Aside: U.S. ethanol fuels suck. I get more backfiring and throttle stumbling.

AMEN !!!!

I think the ethanol fuels are good for the farmers but that's about it. It's a much worse vehicle fuel in many many ways. The boating community is having a very hard time with it eating out the fiberglass tanks and absorbing extra water.

I know I'm loosing approximately 2mpg compared to non California fuel.

I am in the sameish boat. I am running low 30s and a best of 35 on the highway. I have 17/45 gearing though and been yoshed.

Personally, I think I over-yoshed my bike. :thumbdown:

I'm also struggling with mid 30's to high 30s. I'm running 17/43 gearing.

I did the fuel pump mod and believe it really makes a difference in mpg (worse), even with it remapped. I'm thinking to put mine back on the dyno again and work on the low rpm/throttle setting range some more. I runs super smooth but I think it's too rich down low causing the bad mpg, especially around town. It seems I should be able to break into the low 40s at least.

 

[JRWalker]

I know I'm loosing approximately 2mpg compared to non ,,, ,,,

i noticed same 2 mpg lost w/ ethanol blend fuel. so i started using sta-bil ethanol fuel treatment and got back those 2 lost mpg's. works ok for me.

 

[marshallnoise]

I'm also struggling with mid 30's to high 30s. I'm running 17/43 gearing.

I did the fuel pump mod and believe it really makes a difference in mpg (worse), even with it remapped. I'm thinking to put mine back on the dyno again and work on the low rpm/throttle setting range some more. I runs super smooth but I think it's too rich down low causing the bad mpg, especially around town. It seems I should be able to break into the low 40s at least.

That is where I am at. I only adjusted the low speed setting on the Yosh Box and I unfortunately had a broken knob to contend with. Really kind of dumb I know.