Fuel consumption

Thought I'd do an experiment yesterday, riding from Seattle east over Snoqualamie to Ellensburg, then down the Canyon Road to Yakima and back, a series of fast but blind curves along cliff faces bleeding rocks and whatever, but super pavement, most curves marked 35-40 so really at least 60. I was checking my stamina for touring in hotter weather wearing mesh gear over my body armor which is quite hot, total of almost 300 miles in 5 hours. Next time I'll stop more!!

   Long story short, running plus/minus 70 mph up and over the pass and expecting to get maybe 30 mpg, I got @45. 113.2 miles, 2.5 gallons, stock set-up, 6th, 4,000 rpm.

   Does that sound right, or am I running too lean?

Thanks, Joe

I used to drive from Richland to Tacoma a good bit so I know that one! That's a good bit of elevation, temperature and atmosphere changes in that ride so it might be an outlier.

I checked the dash fuel mpg which showed 40 mpg running 80 on the way back. Personally, I liked it slower.

Hello, i had a 2000km. vacation in Scotland, I currently made a rollarisation on my bike, and i noticed that consumption with lower revs, (about 3000 RPM.) gives almost 20 km/liter. whilst driving very slow , about 80 km/hour. now i was wondering are these revs not to low ? , i can go back to 2000rpm without any problem or vibrating. , but i have heard that the drive shaft does not like that. my friend has a Harley road king with similar fuelconsumption , but i think a GRiSO needs more revs to give now problems on the system ?
When revs go up to about minimum 4000-5000 , the consumption increases to 16-17 km/liter. i s that normal? Greetinds Jos

I noticed that lower engine speed gives lower fuel consumption as well but the engine runs silky smooth in around 4800 -5000 rpm.  At this engine speed on hilly roads the bike feels great.    

Maybe lower revs 3500-4000 on flat highway is the way to go for low fuel consumption?

I had a recent experience which pleased me. A 130 mile rip at fast but steady speeds (70-ish mph) and my resulting mileage was 47.7 mpg. My best before that was 46.4 mpg on a 120 mile trip.
I checked my math and confirmed the results. It was a warm day and I didn't screw around with hard acceleration or any stop and go. My bike is stone-stock (but rollered) so I think it runs great.
I've driven your trip in a car and can visualize you on a bike. I'm not too surprised by your mileage.
It stands to reason that long steady high speeds should result in a higher MPG than slower, variable speeds. Remember that you go up Snoqualmie but you also go down it.
I've found the instantaneous MPG display to be useful in choosing the correct gear when climbing a long, steep grade. Also, my dash MPG avg is always lower than my actual MPG.

I usually get around 28 – 35 mpg in downtown commuting and 42 – 47 on the highway but last weekend I took it really easy riding out in the country (no hard acceleration and rarely got over 80 mph) and averaged 58 mpg! (the dash read 48 avg. but the math worked out to 58.) I was stunned and checked it twice. The low fuel light didn't even come on until 165 miles!!

That's amazing. Faster really is better it seems! Now if we could just go fast all the time.

My fuel consumption seems to consistently be a bit lower if I keep the revs in the 3500 and up range. Last few rides, I calculated 47 mpg and on my last ride, 200 miles cruising around 60 mph, I got 50 mpg.

Frontrangerider, I wonder how much your altitude has to do with it?
Less air = less fuel.

I'm sure someone here knows the formula for calculating that.

tvboy - I've wondered about that and I think you are correct.  The air is also less dense so less wind resistance (I think).  On the Tenere, I also get better mileage than what I see in posts by people who live around sea level.  
On the GRiSO, I am running the factory map (closed loop) since my riding here in Colorado occurs at widely varying elevations.  (6,000-11,000').  A local fellow with a Stelvio tried a Beetle map and could not get his bike to run well consistently because of the elevation variations.

FrontRangeRider wrote:

tvboy - I've wondered about that and I think you are correct.  The air is also less dense so less wind resistance (I think).

I think the real reason is that the fuel mixture is made leaner to compensate for the less oxygen in the air.

The other major contributing factor in low fuel consumption is ambient temperature, the warmer it is the less fuel required.

FrontRangeRider wrote:

A local fellow with a Stelvio tried a Beetle map and could not get his bike to run well consistently because of the elevation variations.

Is that right? Did this fellow content me for help?

beetle - I don't know if he contacted you. I just remember seeing his posts on AdvRider indicating that he tried the map, liked what he got initially but when he rode somewhere that the elevation change was significant, his bike did not run smoothly so he went back to the stock map. This was about a year ago so I may not be remembering all the details exactly.

In an earlier thread I posted some stats on fuel consumption over a period of time.

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Thought it may be a useful comparison.

Notice the difference after Beetle mapping.

Pisano wrote:

I noticed that lower engine speed gives lower fuel consumption as well but the engine runs silky smooth in around 4800 -5000 rpm.  At this engine speed on hilly roads the bike feels great.    

Maybe lower revs 3500-4000 on flat highway is the way to go for low fuel consumption?

3,500rpm seems to be the point at which my bike starts to smooth out and feel good. 4,000rpm it’s smooth as butter. Cruising around the ‘burbs on light throttle openings you can easily pull much lower revs, but my bike just “feels” better from 3,500 onwards.

On the highway, noting draconian Aussie speed limits, I sometimes find that the bike can at times labour a bit in 6th gear at 100kph where it’s about 3,500rpm or so. If riding into a decent headwind or slight uphill gradient on the highway, I’ll often pop it back into 5th and the engine will just feel happier and smoother at around 4,000rpm.

Same here Brent. And you're right about the Victorian plod and speed limits.

Keep the revs up and save the planet, we need representation.