Run it until the engine shuts off. I got really close to that point before i chickened out. Put just a little over 19 gallons and was quite a long way to that point from when the dash started giving me warnings.

 

Hmmm . . .I guess I'm a wild man Mike,
I've got you beat there: https://g35driver.com/forums/6330686-post13.html

 

The fuel light comes on when you have only four gallons left. This would give plenty of time for someone to find a gas station to fuel up. So, if your filling up a little after the light comes on, you will put in 17ish gallons.

 

Had a feeling that was coming.

 

lol