I was just wondering how big your gas tank is. I have a 1991 240 (Base) and the manual says it's supposed to be 15.8 gallons -- but I can never get more than 9.9 gallons in my tank when I fill up. I'll run it down to the red-zone at right around 200 miles, and fill it back with about 9.8 or 9.9 gallons.

 

The capacity is around 15 gal. My '90 240 had similar behavior prior to me replacing the gas guage sending unit last summer. It seemed that when the needle just entered the red, I still had 5 gal or more left in the tank.

I replaced my sending unit (for other reasons) and I noticed that it reads much better now. Now when the needle enters the red, I have like 2.5 gal left.

If it were me, I wouldn't do anything to fix it. You should easily make 300 miles on a tank but if you want to play it safe, drive it 250.

 

Even my old 740 was like this....it had an 82 litre (about 20 gallon) tank and always showed empty when I had almost half a tank in it. I never bothered replacing it as it made sure I never ran out of fuel

 

Yeah. My manual said the red zone/reserve was 5 gallons.

 

I have a different problem from the other fuel gauge reading errors. Have had my 89 740 GL for about a month now. Well, I ran the fuel down to the red zone and what do you know, I ran out of gas. Had roadside assistance come by and put in about a gallon - not more - he was spilling the gas as it was going in. Got the car started and pulled into a gas station at the next freeway exit. The pump shut off at 11.2 gallons. I pumped again and got it to 11.8 gallons. The fuel gauge went up beyond the full reading. My manual says the car is supposed to have 15.8 gallons. BTW, I got 316 miles before I ran out of gas. That's about 28 miles to the gallon.

Could it be that I am not able to fill up the tank to 15.8 gallons or is there gas left in the tank that I am not able to use? I could not find anyone with a similar situation. Thanks for any help.

 

Before I replaced my gauge cluster my needle would drop to the red after reaching about halfway. Now I still don't think it's entirely accurate at the lower fuel levels, but it's much better than it was.

 

In tank pump problem maybe?