From about the second tank on, I've been consistently getting 39 mpg. That's a far cry from the mid-40s and 50 I saw so many references to when doing Pre-buy research.
you didn't have enough data points. of all those reports how many ride exactly like you in exactly the same location, with the same conditions, and same fuel amalgam?
oxygenated fuel gets lower mpg than non. altitude and temp also impact mpg. UK (imperial) gallons are larger than US gallons so they report higher mpg than US riders but actual consumption might be closer than it first appears (again, given the same rider, in the same conditions, with the same fuel).
lots of variables. i often get 32mpg. i sometimes get 52 mpg. the difference is getting out of town, running tank-to-tank to get things working well, then running at a higher altitude without oxygenated gas, at a set speed of under 90 on a flat expanse. Cruising at 75 mph in NM typically nets me more mpg than cruising up I35 to OKC at 70. Even though i'm "cruising the slab to OKC, there's more traffic so my speed varies more and the gas is for shit in metro areas.
I learned some years back that it's like trying to compare tread life. you can't tell squat from a rider reporting that x tire gets y miles unless they also provide details on how, where, and conditions of when they got that mileage. the most you can hope for is that they got x with y tire and z with k tire so you can compare tire k if you also had it. there are simply too many variables for a straight up comparison without asking a lot of questions (which i find eventually frustrates those who report basic numbers and don't want to be bothered with all the minutia).