Fuelly?

[jefferson]

This thread got me thinking and I dug out my old trip records. I log the times and mileages for each tank of fuel on my trips. Some fuel for thought. My 89 trip to California for the USGP was 3,924 total miles with a high of 59.75 mpg and a low of 37.56. Avg. was 46.55. Not sure if the euro gears were in or not. Brainerd trip the same year for WSBK was 1,214 total miles with an avg. of 46.73 mpg. High was 53 and low was 44.18. Brainerd in 91 was an unfaired 83 with 1,162 total miles and an avg. of 44.78 mpg. High was 46.49 and low was 40.39. This was a different bike than the other 2 trips. I also logged every tankfull on a different bike and got a low of 31 and a high of 49.49. Most tanks were in the mid to upper 40's. I just didn't record if there were euro gears involved in any of these.

Jeff

[pinholenz]

US36 mpg =6.5L/100km = UK43mpg
US45 mpg =5.23L/100km = UK54mpg
US47 mpg = 5.00L/100km =UK56mpg
US50 mpg = 4.7L/100km = UK60mpg

Your averages look consistent with the gas consumption that I am experiencing.

I'd suggest that consumption less than  5L/100km is careful riding and that consumption above 6.5L/100km is probably aggressive riding or a poorly tuned bike. But US 94mpg (2.5L/100km) has GOT to be top gear idling on frictionless rollers!

http://calculator-converter.com/l_100km_mpg_convert_mpg_to_l_per_100_km.php
http://mpg.webix.co.uk

[dpequip]

For US based riders remember in 1982 REAL gasoline with Real lead was still being sold at the pumps.  Almost all gas sold in US now is blended with at least 10% ethanol more if they think they can get away with it. ( Get a test kit you'll be surprised how much ethanol is actually in the gas) These engines were not designed to run on the crap they sell for fuel in the US so these bikes run worse than they did in 1982 resulting in poor power, and lower mileage figures.  Additionally the rubber and parts in the fuel system on these bike were never made to stand up to ethanol which has very strong solvent properties.  I've owned my Vision since it was brand new in 1984 and now has 30k + miles.  Back in the day (Thru the mid 90s) it got  pretty consistent 45-47 MPG (US Gallons) now those numbers are in the low 40s 40-42 MPG being typical.  I attribute this to the crappy fuel sold in the US and the fact that I have gained about 50 lbs in the last 30 years.   I try to put ethanol free gas in all my motorcycles, small engines, and watercraft.  It does make a difference in how the bikes run and idle when running on real gasoline vs the weasel p*ss they pass off for gas now in US. 

[The Prophet of Doom]

It might be shitty fuel in the US, but it's also the cheapest in the world, thanks to their agressive foreign policy

[don_vanecek]

hey dpequip, welcome, where have you been all these years?  Anyway...quoting you...."Back in the day (Thru the mid 90s) it got  pretty consistent 45-47 MPG (US Gallons) now those numbers are in the low 40s 40-42 MPG being typical.  I attribute this to the crappy fuel sold in the US and the fact that I have gained about 50 lbs in the last 30 years"......let me tell you buddy that is pretty much just what I have experienced..unfortunately I wish the gain in weight had not happened but it's a reality. 

I think there is one other factor to consider....we don't drive 55, we drive (speaking for myself anyway) 65, 70, and more..I think that's another factor.  Jeff, some of your trips sound pretty good but weren't those at the old 55 days also? you most likely didn't drive that speed but using the old don't go more then 10 over, I'll bet you didn't go 70-75 in the 55 zones where, traffic allowing, I won't think too badly of doing 70-74 in  65 zone today.   

[QBS]

Alcohol debased gasoline contains fewer BTUs than pure gasoline and therefore delivers fewer mpgs.

[dpequip]

Promise you "back in the day" 55 was just a suggestion when I rode. So I don't think speed is a factor in my reduced mileage figures.   I have plenty of old blue paper slips from law enforcement to prove so.  Yes ethanol has less BTUs and that is root of the problem.  Ethanol also has other undesirable properties as a motor fuel like attracting water.  Fuel injected vehicles seem to be less sensitive to ethanol based fuels but any vehicle with a carburetor seems to be negatively effected by ethanol based fuels.  This actually makes sense because in the US market anything old enough to have a carburetor (Automobiles  / Motorcycles) were never engineered to run on ethanol based fuels.  Before ethanol, in the US market an additive called MBTE was used to oxygenate gasoline.  While MBTE was not gasoline it was blended in a much smaller percentages so it had less of an effect on the operation of these engines.   We might have cheap gas in the US but you get what you pay for and the gasoline sold in the US doesn't even smell like gas anymore it smells like paint thinner.  About the only place to get decent gas is the race track.

[tig5]

In case anyone is interested there are also apps for iphone and android that do a similar if not better job. I think the one I used on our Pan-American scooter trip was called Gas Buddy. You can have profiles for multiple bikes, enter info such as price, quantity of fuel, odometer readings etc and it will spit out a number of useful graphs and statistics.
Regarding inconsistencies in a "full tank" scenario, can you not just enter the amount of gallons purchased and avoid any inconsistencies caused by an unusually shaped tank that is hard to fill right up?
The smartphone tools are handy as you can do them right at the pump with the information on hand. Just my thoughts.