Originally Posted by GillyWI
I just got back from a 3 day trip to the Michigan UP (the new rain suit works fine).
On the last day in to the trip, I noticed my trip computer was showing up over 50 mpg, which it had never read that high before. My distance to empty, after a fill up was way higher than I thought it should read. Initial calculation was around 302mi, and went up a little even, up to around 308. Took around 100 miles before it went below 300! It did eventually go down to what I would call a reasonable reading. Sort of what I've noticed before, the distance to empty falls rather quickly towards the end. I am just wondering if this was caused by the highway miles, which I am not used to doing strictly highway stuff. Or maybe the engine is getting broken in? I rolled 5K on this trip.
The slow-at-first, faster-near-the-end rates are commonly reported for both the fuel remaining "gauge" and the distance-to-empty computation. I have not seen published information on how
distance-to-empty is computed. Based on information I have seen from others, my guess
is that the computer keeps a rolling "mpg" window, and multiples fuel remaining times the windowed mpg. Because the estimate of fuel remaining is somewhat flawed, the distance to empty is equally flawed, and thus appears to drop faster near the bottom of the tank.
The computed mpg is almost always optimistic. For my 2007 K1200GT, the computer computes 2-3 mpg too high in mixed city/highway, but is somewhat closer (still 1-2 mpg too high) on long slab highway rides averaging 70 mph or so.
You can find a two year history showing gas mileage (reported and actual) and other fuel usage and maintenance information posted at:
The latest data is at post #47.
Regarding your other question about whether a K1200GT can get 300 miles on a tank:
With a 6.3 gallon tank, you would have to average a true 48 mpg. Note that the filler neck may prevent you from getting a full 6.3 gallons into the tank. The longest range I have achieved on one tank is 255 miles. The best actual mileage that I have seen is 46.4 mpg. (The OBC reported 49.0 mpg.)
Bottom line: I believe it is possible to squeeze 300 miles from a KGT tank, under optimum conditions of fuel quality, altitude, speed, wind, etc. If you deliberately set out to do it, you could plan a ride that would achieve 300 miles on a tank to prove the point, but don't count on it for an ordinary trip.
(Note: Some people have auxiliary fuel cells attached to their bikes, or carry Sigg fuel bottles on rallies to extend their range.)