Ok, here's one more input:

2004 with 29000mi, GIVI 46 top box, oversize shield, K&N airfilter, Mobil MX4 syn oil, few other farkles that don't influence mileage. IBA rides, lots of twisty roads whenever possible, avoid interstates like the plague. I don't baby this bike-that's stupid. It's made to run at 100mph all day long. And I get as close to that as possible as often as possible when conditions and LE allows. And with few exceptions I ALWAYS get over 40mpg. A typical 600mi day I'll get 42mpg always using regular fuel-stay away from premium. I've gotten as high as 48mpg and as low as 37-both very rare. and yes, altitude does matter. I live at 4000ft and there is probably a 2-3mpg difference as you go much lower or higher.

Can't imagine ever wanting another bike as much as I still want this one!

Ride safe-and fast.

Dirk