I've got an 800 intruder and i'm a big guy, about 250 pounds, and i get about 34 miles to the gallon around town and on campus, the speed limit being 20 miles an hour. Does this sound right? What should i expect on the highway at 60-65 mph (aka 100-110km/h)? I was hoping to get about 42 on the highway. This, of course, is US gallons. I got 85 miles on the last tank and filled up with 2.5 gallons of gas, which equals 34 miles to the gallon.
That sounds a little on the low side of the range 30 to 40 mpg but both situations you describe are not max mpg speeds. For max mpg range you should ride in the 45 to 50 mph range.