My 2001 XJ (also auto) has 2 gallons left when the fuel light comes on. I've gotta think there's a lot of variance between vehicles so yours may be a little more or a little less.

 

Thanks guys. First tank it came on today at 310 miles and I got fuel just after.

 

my light comes on and starts switching between on and off juuuuust after a quarter tank and it plays that game for a long time till about half way to E

 

The fuel gauge in my 98 fluctuates quite a bit under 1/4. That light makes you want to get gas just in case the freakin thing decides to be accurate for once. But I have driven quite a few miles with the amber light of impending doom lit up.

 

My fuel gauge when about half full will move about a quarter of tank when I turn a sharp corner lol! But my light varies too much. I don't trust my gauge so if I do let the light go on I get gas right away. I've done 15 miles of city stop and go traffic and it died as I pulled up to the gas station. The gas station was closed for maintenance so I had to wait for 2 hours because I ran out of AAA roadside assistance things LOL

 

And all of that, ladies, is why any method of "calculating" your gas mileage that involves your gas gauge in any way, is completely and utterly bogus.

 

I think it's completely and utterly bogus to bring a dead thread from 2011 back to life. Nicos96XJ came out of the hole running full speed with his first post. lol

 

Last weekend I put 18.5 gals in my 90....(it has never taken 20). Light hadn't come on. 16-22 Mpg depending. Upshot, don't count of going far after it's on.

 

There should be about 4 gallons left when the fuel light comes on. I drove my until the light came on and then went straight to the gas station, the pumped stopped at 16 gallons, I did this 2 more times just to confirm.

 

My 96 xj does the flucuating after 1/4 tank. Light came on so i threw a couple gallons in and went bk to 1/4 mark