Originally Posted by randel
That's still one of the biggest fuel tanks offered for current big adventure bikes. Yamaha S10 has 23liters (261kg), BMW 1200GS 20liters (229kg) and Ducati MS1200 20liters (220kg). Only exception is BMW GS Adventure with 33liters (256kg).
That's enough for Europe and most adventure touring I can think of from my point of view. Of course it may be different for US and Australia.
You missed the other exception - Moto Guzzi Stelvio (32L)
I used to be pretty hung-up about tank range and my 955i Tiger was pretty good with typically 215 miles in between fills (often did more). You can easily convince yourself that you need a bigger and bigger tank so that you don't need to visit a petrol station every day whilst touring and there certainly are benefits to that.
I then looked at the way I ride, most of the time. I'm not doing super long adventure tours, just hooning around with the occasional jolly to Wales, France or Spain and some local off-roading. I don't do much off-roading but I like the feel of a proper sporty trail bike on the road as well. My current 990 would just about get to 200 miles between fills if I take it easy but my normal fill-up range has just dropped by about 30-40 miles. So far, it hasn't been an issue and I can tap the benefits of the Adventure more than I can benefit form the desert fuel range of a more road-focussed/heavier bike.
If I ever embark on that desert-tour, I'll be spending a small fortune anyway so the modifications to carry extra fuel will be a drop in the ocean. If I do another Euro-tour, I'll take a collapsible fuel tank at the bottom of a pannier and probably leave it there, empty.
The exception is for those of us who regularly do distance on a daily basis such as long-distance commuting. I can fully understand why you would then select a bike based on range above (almost) anything else. The Guzzi and the GSA seem to have the edge here because they also have shaft drive.
I don't think you can win. Even GSA riders must have, on occasion, wished for a longer range when their reserve light flashed on and forced an inconvenient stop.