Interesting figure. 3.8 liter per 100 that's 26 km per liter. This is mind boggling economy and I do not believe it. Do not want to sound bad, but without relation to any particular bike model this figure is worthy of participation in "fuel saving races" for which people building purpose machines.
I agree with TwoPlugs figures on old Transalp (just finished rebuilding mechanics and getting to run 88 transalp for a friend) - 5 liter per 100 is achievable in easy motorway riding in top gear and no headwind. Less means very steady riding or slightly lean mixture (no big deal for Transalp).
But 3.8 on even new Varadero (that guy says his Vara is 2003 model) means either that you cruise on boring motorway with wind to your back in top gear without even as much as feathering trottle or that your bike runs really really lean + half of above conditions. BTW - notice that in blog you mentioned rider did find that his bike was running very lean and fixed it.
3.8 means that Varadero is the most fuel efficient motorcycle ever built...yeah, of course.
At risk of getting another portion of "rotten tomatoes" from Varadero owners from what we read before Varadero is most reliable, roadworthy, fastest, fully dirt road friendly than any competition, eats any other bike for breakfast in any condition, sold in huge numbers, cherished by world motopress and generally ruling the rooster of world motorcycle building and now it is most fuel efficient too! Ah, and best dualsport motorcycle in the world, rooting it's history to RC51 and Superblackbird...
No offence, but sometimes I what I read sounds like marketing campaign. Why not just to say that Varadero is good bike for segment of market it was built for? You just sooo dedicated guys! Now Varadero granted sales success in USA!
How hunting season open, you welcome to shoot