I have the 32 gallon tank, my warning beep & light come on right around 55 miles until empty
i have had to drive until it went down to 20, but i didn't like it at all
the fuel pump depends on the gas to keep it cooled off
I had passed the Golden Acorn when the light lit up, it was close to 10 pm, luckily it almost all down hill to El Cajon from there.
Just the Immigration Check Point & Pine Valley Bridge hills to climb.
I had plenty of gas in the auxiliary tank, but it is as dark as hell out that way & i forgot to turn off at Tavern Rd