Computer MPG vs Actual MPG

[eeksnake]

'07 w/35K

Computer's AVG MPG has consistently been within +/- 1 MPG in comparison to Odometer/Gallons dispensed (using calculator).

Many, many variables to consider... Rider(s) weight... Fuel quality (read Ethanol ratio)... Wind... Riding style... Tire inflation... Etc.

I use the on-board AVG MPG as a guide along with knowledge gained through experience of riding in as many different conditions as I can. My "normal" range is 200 miles for trip planning. That leaves me plenty of fudge room for conditions (traffic, wind, etc.). I much prefer to rely on the computer than the old tried-and-true "slosh and listen" method from my Harley days.

 

[Checkswrecks]

I know I am know were near expert here since I have only put 1800 miles on my bike so far but this is what I have found. First off I use this bike as a commuter. 99% Freeway with side cases and Givi 52L trunk 100% of the time and a VStream windshield. Also I am 6'4 and 255lbs. This is what I have found. At 80mph I get around 37-38mpg consistantly measured with fillups by calculator and at about 200 miles my low fuel light is on. This past few tanks I tried to keep my speed at 65-70mph and I was getting 42mpg's. Bad part about the last experiment is the FJR does not like to go slow and I hate cars passing me all the time. Guess I will just have to bite the bullet and take the decrease in MPG to keep the smile on my face. I have to admit I am not all the impressed with the FJR's MPG. I went on a ride with my friend who is riding the new Connie and he got better fuel mileage than I did. Not sure how far I can go with my low fuel light on but I think probably best case senario is I can go about 220-230 miles on a tank. Oh ya I also have only ran with Regular Unleaded. Anyone know how far you can go after your low fuel light comes on?

Using a calculator, I got pretty consistent 47-48 overall real mpg (pumped gallons, gps-corrected miles, and a calculator) on the 2004 and so far the 2007 is very close to the same. The display on my 2007 is slightly off, but about the same as the speedo error. There are plenty of threads about speedo error and MPG in NEPRT-land, which is where this one appears to be headed.

To get better mileage, obviously shift up as soon as possible, keep the tire pressures up, slower is better, and one that most people don't recognize is to try not to move the throttle once you're at some speed - if you do move the throttle, try to do it very slowly. This keeps the computer from making the mixture a bit richer every time you increase throttle. (Think back to the accelerator pump in car carburetors.)

Bob

 

[charon76]

Anyone know how far you can go after your low fuel light comes on?

Till she stops! :yahoo: In theory with over a gallon left 40 to 50 miles. Not sure how trusting I am of that however.

 

[ELP_JC]

I'll embark on my first trip on this bike Sunday, and more than precise MPG, all I care is about RANGE. Seems like 200 is a nice, conservative figure, with plenty of reserve; that used to be the MAX range on my BMW K1200 so I'm happy with that. Will try to be able to run a bit low on gas, to see where I get the low fuel light, so I know. One variable not mentioned which makes a big difference is ALTITUDE. I ride mostly on the mountains, so I should be getting at least 40s average. I do ride fast though, but alone, and am just 155#.

As far as MPG being good, for a bike yes, but it's a bit ironic you'd get the same on a Civic at the same speeds. Most of us don't care, but I don't consider it 'good' in general . Later gang.

JC

 

[Harald]

Ok. It's not Friday. I did the searches. And I don't actually mind the gleeful snarkiness anyway. Took the bike for a spin around Hood Canal and I rode in a fairly sedate manner, most of the time. I filled up with fuel first thing, on the center stand, to a level that I could eyeball so I could repeat. I reset a trip meter and I reset the Avg MPG on the computer.
I rode almost exactly one tanks worth of gas and refilled near the house. I re-filled on the center stand and eyeballed it to the same level, give or take an ounce. The tripmeter read 216.3 miles elapsed, and I put in 5.351 gallons. This equates to 40.42 MPG. The Avg MPG according to the computer was 49. 3 MPG. I was very pleased during the ride, but I have to believe the calculator is more accurate. The only thing I missed doing was checking the odometer for accuracy against the mile posts.

(Actually the 40 isn't all that bad considering I was riding two-up)

So, all of you posting high 40's in fuel economy (like my bike reports), are you using the calculator or going by the computer?

Do you by chance have a Power Commander installed?

My 07 used to get around 40mpg calculated and only slightly higher on the computer. After I installed the PC-III, my mileage dropped to around 36mpg, but now the computer is showing much higher (more like 43 mpg).

BTW, we have the same driving conditions and gas supply because I'm just outside Bonney Lake city limits and probably fill at the same stations you do. Which reminds me, the Shell at the bottom of 410 downhill from Bonney Lake might have sold me some bad gas because the bike actually sputtered when I got home a few miles after filling up there. It's running fine today though.

 

[Rondo777]

My Computer was extreamly accurate for the first 10k miles. AVG around town was always 40 - 41mpg, according to both the trip computer and a calculator. HiWay consistant 49 - 51mpg. Now that the Power Commander is in there, game over! Actual MPG have dropped to about 36mpg city and HiWay to around 45. The trip computer is saying more like 60 Avg mpg all the time.

 

[Beamer Reamer]

You guys are probably on to the issue. I started this post right after I installed the power commander. I used the combination Wally Smoothness/Holeshot to start out with and have not experimented from there. I love what the PCIII has done for the bike at the low end - an incredible difference. Other than a few jack rabbit starts and passing cars at around 100mph, I kept the bike at about an average of 3000RPM while cruising, maybe just a tad higher. I bet it is the PCIII throwing off the numbers.

 

[Checkswrecks]

You guys are probably on to the issue. I started this post right after I installed the power commander. I used the combination Wally Smoothness/Holeshot to start out with and have not experimented from there. I love what the PCIII has done for the bike at the low end - an incredible difference. Other than a few jack rabbit starts and passing cars at around 100mph, I kept the bike at about an average of 3000RPM while cruising, maybe just a tad higher. I bet it is the PCIII throwing off the numbers.

Bingo.

The PC3 basically works by mis-leading the ECU computer and does this by altering what inputs the ECU sees from the bike's sensors. Since the mpg display is coming from the ECU, garbage in = garbage out.

 

[fjrboomer]

I have an 07A and ride solo and weigh about 170. The computer is usually within about 2 mpg of the calculator. I am getting 46-48 mpg riding within 5mph of the limit on highway driving except for passing where I occasionally reach speeds of 90 by the speedo. My best by calculator was 49.8 mpg. I use regular gas (no ethanol). Ethanol drops the mileage about 2mpg. I have the stock sheild and ride with it in the lowest position most of the time.

 

[ahchiu]

I'm getting a 2006 FJR on the 18th of this month, can anyone tell me if it has a FUEL TRIP ODO when the LOW FUEL light comes on, the R6 starts counting miles when the light comes on.

Thanks,

Marcus

 

[DaveInMn]

When ridden conservatively, under good conditions (e.g. little or no wind), the computer on mine is usually very close to actual. When ridden with a heavy right wrist and/or into a stiff wind, its a of a bit more, but usually still within 2-3 MPG.

Best mileage I ever got was on the Natchez Trace (speed limit 50, doing an indicated 55, no wind) was 57 MPG (actual). And that was when the bike had less than 2k on it. Now, usually in the 43-47 range (actual).

 

[LDRydr]

In Oregon I need to do the speed limit and I was getting around 36 but I never really get any higher than that but I also have a tall windsheild and and likely weigh more than you.

The state-mandated year-round crappy 10% ethanol blend in Oregon will shave at least 10% (or more) off your mileage. You'll get more accurate readings in a different state. CLICKY

 

[ELP_JC]

can anyone tell me if it has a FUEL TRIP ODO when the LOW FUEL light comes on, the R6 starts counting miles when the light comes on.

Yup. And it's like a 3rd trip meter; it pops up along with the fuel light. I haven't gone that low yet, so you better get confirmation from somebody else; I might be remembering some other bike :dribble: . And my bike is an '07, but I assume identical in that respect. Take care.

JC

 

[Rondo777]

can anyone tell me if it has a FUEL TRIP ODO when the LOW FUEL light comes on, the R6 starts counting miles when the light comes on.

Yup. And it's like a 3rd trip meter; it pops up along with the fuel light. I haven't gone that low yet, so you better get confirmation from somebody else; I might be remembering some other bike :dribble: . And my bike is an '07, but I assume identical in that respect. Take care.

JC

I've gone that low and it works. You hit reserve and it starts counting up for you.

 

[Harald]

And I've gone 50 miles into the reserve and the bike was still running. I believe I still had a half gallon of fuel left when I filled up.

 

[ELP_JC]

And I've gone 50 miles into the reserve and the bike was still running. I believe I still had a half gallon of fuel left when I filled up.

You were probably running in fumes buddy. Remember the bike can't use all the fuel, or the fuel pump would burn. For what I've read, you're pushing your luck above 30. Good day.

JC

 

[LDRydr]

And I've gone 50 miles into the reserve and the bike was still running. I believe I still had a half gallon of fuel left when I filled up.

You were probably running in fumes buddy. Remember the bike can't use all the fuel, or the fuel pump would burn. For what I've read, you're pushing your luck above 30. Good day.

JC

This all depends on the mileage you're getting at the time. I've been above 40 on reserve more times than I can count, and into 50 a few times, even with an AVG MPG showing in the high 30's. Strap on a small gas can (or have a friend in a cage follow you with one) and run it up and see where it will go. Riding a Harley for so many years I used to start sweating when my fuel light came on. Not any more.

 

[FJR1300Mark]

The last two fill ups I got an odometer calculated 44 and 45 mpg.

It really does depend on speed and riding conditions.

My bike computer always seems to read a little higher.

 

[grendell]

I have found the bike computer to usually be 5-10 MPG over the calculator on my 06AE. I reset the average MPG reading after every fill-up.

Ok. It's not Friday. I did the searches. And I don't actually mind the gleeful snarkiness anyway. Took the bike for a spin around Hood Canal and I rode in a fairly sedate manner, most of the time. I filled up with fuel first thing, on the center stand, to a level that I could eyeball so I could repeat. I reset a trip meter and I reset the Avg MPG on the computer.
I rode almost exactly one tanks worth of gas and refilled near the house. I re-filled on the center stand and eyeballed it to the same level, give or take an ounce. The tripmeter read 216.3 miles elapsed, and I put in 5.351 gallons. This equates to 40.42 MPG. The Avg MPG according to the computer was 49. 3 MPG. I was very pleased during the ride, but I have to believe the calculator is more accurate. The only thing I missed doing was checking the odometer for accuracy against the mile posts.

(Actually the 40 isn't all that bad considering I was riding two-up)

So, all of you posting high 40's in fuel economy (like my bike reports), are you using the calculator or going by the computer?

 

[mcatrophy]

QUOTE (Beamer Reamer @ Sep 7 2008, 05:44 AM) <{POST_SNAPBACK}>

...

So, all of you posting high 40's in fuel economy (like my bike reports), are you using the calculator or going by the computer?

I find the computer reasonably accurate over longer runs. I think it ignores fuel used when idling.

FWIW my consumption is fully documented, click on the graph to see the full information.



(The graph will remain up-to-date.)