I always reset my trip meter every time I fill up and have done so all my life on every bike I've owned. My 2017 SDR is supposed to have 10% better fuel economy than the previous 1290 but I can't compare after coming away from the 990SD. Considering the tank size on my bike is the same as my old 990 (18 litres) the fuel economy is incredible.
With enthusiastic riding I would see 130 miles before the fuel light came up on my 990,and once I made it to almost 150 miles. But yesterday I gazed down on my 1290's trip meter and was astonished! I kept gazing down thinking to myself no way, and the warning fuel light came on at a staggering 176 miles.
When I first picked up the bike from the dealer, I noticed the fuel range said 170 miles and saying to the chap that I couldn't see that happening and laughing. It is truly amazing that the engine produces more power and is so efficient, ( not that I bought this type of bike for fuel economy).

I was out with a mate today, thats got a standard 17, my light came on at 152, his was not on, so don't know how many miles he had left

My 990 does about 100 miles before the light comes on. Never worked out what it actually did to the gallon, doesn't interest me really. Unlike my 750 Kawasaki triple which only does 60 miles until reserve and about 5 - 10 tense miles on reserve until it runs dry. Does 19 to the gallon so petrol stations are your friend.

I normally manage 130 miles to a tank before the light comes on as well.

120 miles light to light for me, 50% open road and 50% central London.

Not managed 130 yet, regularly get 110 before the light... and maybe had a 120.. once...

TBH I'm still a bit too throttle happy on the SD as it's still quite new to me.. and I have another bike for doing the mundane stuff... a '07 DL650 which regularly does 250 miles between fill ups, and could easily do more, and is also still fun in the twisties so is a pretty good touring bike.

I regularly get 14.5Km/L (40.1Mpg UK / 34.1 MPG US) commuting in 60-70kmh zones. A little stop start traffic....
So safely about 240-250km per tank. Light goes off around 220-230 kms.
I have ridden 270+km twice.....I was new to the bike and fuel sensor wasn't working (I put in 19L both times).
First time ran out rolling into the fuel station driveway, second time ran out and flicked the bike to the left a few times, up the Gateway Bridge southbound (when rolling at about 50kmh) and just got enough fuel to the left side of the tank to ride the 1 km to a fuel station. Probably one of the worst places to break down too (I ordered the fuel sensor the next day).

I even got 18Km/L when riding with a group on the back roads sitting on 80kmh. Was boring as F@ck though....lol.