The best way to find empty is to leave your cell phone home, come to North Carolina in August and drive until the car quits. Walk to the gas station, get some gas or diesel and walk back. When this happened to me, I found out that empty is whenever the guage goes below 1/4 tank it is time for a fuel stop, empty or not. :)

The other than US versions of the w210 chassis came with a minimum 60 liter capacity. The US market usually gets all the luxuries and by default get the 80 liter tank. From what I read the smaller 60 or 65 liter unit has a square in the middle of it to allow for a "ski-boot" like access to the rear seat....

Correct me if I'm wrong someone.

I have got 24 before when it was running on fumes at the pump. That is with slowly pushing 4 gals in after it clicks off.

If there is any, I suppose. Aren't the tanks gravity fed tho? IIRC, there is a sock filter at the bottom and we attached the lines from the bottom.

A lot sooner than you'd think
 

Empty on my '99 W210 TD is slightly below the 1/4 tank tickmark, but above where the (alleged) low fuel warning light comes on.

Not on mine.

AFAIK, my '96 has a 65 liter tank (per owner's manual -- 16.4 gallons). Perhaps they went to a larger size in 1998?

22.734 gallons, and still takin' it
 

......when pump cut-off @ $75.00 worth of diesel. --22.734 gallons. Wasn't empty yet!

The 98-99 is a 70L tank with an additional 10L reserve for 80L/21.1 gals total.

Anoyne who has put more in is mistaken or a mech has run compressed air in the tank in a vain attempt to push fuel up to the IP and blown out the alumimun walls of the tank.

24 gallons, is what I believe it takes from dry.

Well here is what my VIN Data Sheet shows.
 

915 fuel tank, 70 liter (с 01.05.1988)

That is basically 18.5 Gallons. So that does not make any sense. I was thinking it was 20 gallons plus the reserve personally.

I now have purposefully brought more confusion than clarification.

If it were not snowing I would wander out to the shop and check the owners manual.

Im poor. I havent seen my tank over 1/2 in probably two months. I always run In reserve, carrying two gallons of diesel in my trunk with me at all times.