Thanks to smartphones, we quickly found the size of his gas tank online, which turned out to be larger than he thought. OK. Keep track of your distance and fuel and we'll figure this out. At the end of the day, he was asked how much fuel he had put in at his gas stops. He had no idea. Let's see your receipts. He hadn't kept them and didn’t note his mileage.
This may be fine if you are out for a casual ride on your own, but if you are part of a group, you should know if you can keep up or if you will require extra stops. Nobody wants to be Ben Spies at Monza in 2009 (where he ran out of gas on the last lap while in the lead), but do you really want your travels to include every gas station along your route?
I carry a small notebook in all my vehicles. I log every gas stop including my mileage, where I was, how much fuel I pumped and what station it was. I will include dates and mileages of service such as oil and tire changes. All of this lets me know how far I can ride. I also know if I have to do any maintenance before a trip.
Tracking the amount of fuel I use and knowing how far I can reasonably expect to go on a tank of gas is a good baseline. From the baseline you also have to take into account the conditions under which you are riding. With the large 29 litre gas tank on my Honda ST1300, I am confident that pushing 500 km or more between fill-ups in ideal conditions is not a problem. When I do Iron Butt rides I generally like to plan fuel stops between 400 - 450 km, which breaks the 1600 km (1000 miles) into nice chunks. On one ride I went 383 km and filled up. I then turned around and went back 395 km for my next fill. The wind was behind me on the first leg and in my face on the return trip. I used an extra 4.7 litres of fuel riding into the wind, but wasn't concerned about my consumption and was able to stick to my plan because I knew I had plenty of reserve in the tank.
Ride reviews often document the size of fuel tanks and sometimes include consumption figures from their test rides, but it's best to track your own real-world mileage figures. You'll be able to do more riding and less pumping.
Ride responsibly and enjoy your travels.-- R. Bruce Thomas