How much gas does a 2.5L Rocket really hold ?

[Idaho Red Rocket 3]

My new to me 2023 R3 GT does not have a long range for me. It seams to me that just a short 80 mile ride uses more than half the fuel in the tank. Just the other day I desided to run the tank down to only a few mies left on the miles to empty read out. I stay closer to my favorite Non-Ethanol gas station as I got closer to 0 miles. Finally ran it down to 2 miles and headed to the gas station. As I pulled up to turn into the station it clicked over to 1 mile remaining. I filled up. It took 4.17 US gallons. Is this typical ?

 

[Rockatansky]

From my point of view your idea is wrong - you did not verify the volume of the tank, you checked how much volume you can enter based on an information on the display.

If you really want to know the volume, you have to drive until it stops and then refill.

Problem: this only works with somebody following you and filling you up directly after you stopped - because even by using a spare liter to fill up after stopping already creates a false result based on the distance you have to ride with the safety liter to the next filling station.

We made it that way with a nearly new GT in 23 ("nearly new" because it had some kilometers on it but we wanted to have a clean tank for the test) and arrived at about 18,5 liters volume - which is fine for me, because the tank also carries some stuff inside. By the way: the kilometers to go on the display had been 0 for a very long time... if I remember well around 70 km or so...

 

[rick danger]

My new to me 2023 R3 GT does not have a long range for me. It seams to me that just a short 80 mile ride uses more than half the fuel in the tank. Just the other day I desided to run the tank down to only a few mies left on the miles to empty read out. I stay closer to my favorite Non-Ethanol gas station as I got closer to 0 miles. Finally ran it down to 2 miles and headed to the gas station. As I pulled up to turn into the station it clicked over to 1 mile remaining. I filled up. It took 4.17 US gallons. Is this typical ?

Good research. Its supposed to hold 18 liters/4.8 gallons. so at 32 mpg you should get about 20 miles more when the range reads zero, according to what should be left (4.8 minus 4.17). Although @Rockatansky says twice that. Terrible range on these bikes. The big drawback for touring on them. which is what I'm going to try to do. I bought a 1 gallon fuel bag to put in my tank bag. Just might save me a walk one day. Or a long wait for a tow place to bring some....as an aside, running them empty might be hard on the fuel pump. Fuel keeps it cool

 

[Jagster]

Getting to know what the fuel gauge reading is really telling you, is a very worthwhile exercise.
I'm guessing that different bikes will have slightly different readings, so worth doing your own rather than relaying too heavily on what other folks recommend from their bikes.
In the case of the 2.5 Rocket, the range very much depends on how the bike is being ridden.
It's easy to run dry in a pitifully short distance if emotive expression is turned up to eleven, but if i'm on a tour and cruising comfortably for a run of say, 4 hours in the saddle,
I can easily get 125miles (if I try a bit harder 140 miles).
For UK riding distances, that's generally acceptable.