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...