97 TJ Fuel Reserve

Does anyone know at what point the "low fuel" alert triggers on 1997 TJ's? I have an SE with the tank configured for 15 gal. When I fill the tank the most I can put in before the pump trips is 15-16gals, so no surprises there but the gauge only reads 3/4 full. It's possible I have a bad sender or a previous owner installed a fuel pump for the 20gal tank. Either way I don't really trust the gauge/sender. Thus I'm trying to determine some realities of the high and low limits of the tank. Without driving until I sputter and die on the side of the road (alone in the rain).

 

Notoriously inaccurate low fuel indicators on the TJ"s. You can have two identical models and might have a 2 gallon variance when the low fuel light comes on.
Should have between 2 and 4 gallons left when low fuel light comes on regardless of tank volume.
TJ's only had a 19 gallon tank, but for some reason, Jeep used a longer vent line protruding into the tank on some models that forces the gas pump to shut off at 15 gallons.
Fuel pumps are the same, but the float sending unit is different for 15 or 19 gallon.
If a 19 gallon pump ends up in a tank that will only fill to 15 gallons, it will read 3/4 on a full tank.
Instead of changing the pump, you can cut the vent line so it only protrudes into the tank about 1 inch and you'll have a 19 gallon tank.

 

Thanks for the info. I'd know about the tube "trick" and plan on doing that just as soon as the weather changes and makes it less fun to bop around and more fun to bang knuckles. What I really appreciate is the low fuel alert volume. When asked the local Dodge Jeep dealership was all "Oh, impossible to say. No way or knowing. That info isn't published." Yeah whatever. Your comment aligns with another post saying the "reserve" was 2.8 -3gals. Based on your info, I'd say my "Lil dog" holds on to something closer to the 4gal mark.