When I first got mine (9600 miles) the light would always come on around 145; then I took my first big trip of 350 miles each way (odometer was then 16,000+ miles) and started getting 175+; now I am consistently in the high 180's & sometimes 200+; this is even 2-up w/ overnight packing.
About 180 mi is a good average for me. Since I consistently get about 50 mpg, I usually wait until about 200 miles on the trip odometer before I stop for a fill up. This is with daily commuting -- a 75/25 mix of highway & local driving.
2005 R1150R -- Granite Grey Metallic
Lifetime Member #566
I did a search for the "filler cap mod" and got nothing. I will also say that when I do a search on other web sites for car stuff I have no trouble getting exactly what I am looking for, but on this site if I put in"Mexico" for example, I'll get back something on tacos or other loosely related stuff-