Somewhere we had a discussion about minimum MPG, but I can't find that, so here's a new thread
So, I finally did the "minimum mpg on a V650" Autobahn run. In the interest of science, of corse! One warm summer evening, I was using the oppurtuinty of a 300 km Autobahn journey that I had to do anyways. Traffic was neglible.
My setup is a 2008 Versys running without a windshield (it was really hot during the day), a large top box, hand guards, and a high GPS mount. I'm a tall/slimish guy (1,90m/85kg) dressed in textile with a flappy high-visibility-vest over it. Not optimal to achieve the highest possible top speed, but we're interested in low MPG, so full throttle = full throttle. My versys is equipped with a speedohealer and GPS, and I know that the speed reading in stock is too high and distance traveled as shown by the versys is mostly accurate, which I accounted for to obtain in the following numbers
I also verified the distance using google maps.
Tires were BT023 with 2 mm or so remaining (1.6mm being the legal minimum in Germany), so I had to replace them later anyways (going fast kills rear tires).
So, at first, I did my regular cruising speed of 150 km/h for 200 km between two Autobahn pump stations, resulting in an average consumption of 6.21 l/100 km, that's 37.88 mpg at 93.2 mph over 124 miles for our non-metric friends
The next pump station was 71 km (44.1 miles) away, so I went "full throttle" until there. There was only a short construction site with speed limit and a minimum of slower traffic on the way. My top speed was only around 180 km/h (112 mph) due to the lack of a windshield. I've seen 195 kph (121mph) on the tacho before with a windshield (and 211 kph=131 mph without speedohealer).
Thus, 6.17 litres for 71 km equals 8.69 l per 100 km
Or, in "imperial" units as converted by google, 27.1 mpg.
That's a 45% higher fuel consumption at 180 than at 150, which is a 20% higher speed. Which is almost quadratic as a scientist would expect: 1.2^2=1.44.
In other words, I wasted 1,76 liters of fuel = 3 euro = $3.93 to save 4 minutes and 44 seconds.
In general, going that fast is not worth it. The faster you go, the less time you save by going even faster.
And not only does it waste fuel, it also eats up rubber, especially the rear tire.
It's uncomfortable as hell - don't even think about doing this without hearing protection.
The traffic ahead of you has no chance to correctly estimate your speed, especially at night.
So this was a one-off show for me, other instances of high speed were only for a few minutes for the thrill of it, or the get rid of annoying vehicles.
btw, the current fuel price in Germany is 1.709 Euro per litre, so somewhat around $5.92 per gallon (cheapest gas, 10% Ethanol 95 Octane).