Fuel Capacity for 1982 300SD - PeachParts Mercedes-Benz Forum

anhydrous7 · #1 09-18-2002, 03:51 PM

I performed a search to see if I could determine the fuel capacity for my 1982 300SD. I was not succesful in finding a thread that addressed the 300SD specifically. I acqired a Mercedes shop manual on CD for the 126 chasis. In there, I was able to find information that indicates that U.S. 300SD models '81 and newer have 77 litres at "full readout" (this wording must be from a literal German tranlation). The reserve capaicity was given at 12 litres.

It is my understanding that this reserve capicity is part of the 77 litres. I imagine the standpipe/screen combination is what provides the 12 litres. I also believe that the low fuel light comes on when there is 12 litres left in the tank. That is, if all of the systems are operating correctly. Is this a correct assumption about the low fuel light? I have not let the fuel level get that low.

I then converted litres to gallons, and I came up with approximately 20 gallons of capacity. (I used 1 litre equals 0.26 gallons for the calculation) Unfortunately, the Owners Manual was not with the car when I purchased it. I was hoping someone might have a manual for this car that can confirm this information.

I have fueled up five times now since purchasing the car in August. I am getting an overall average of 25.74 MPG. I think this is right in line with what is typical of the 300SD. Most of my driving is highway.

Regards,
Rob

#2 09-18-2002, 04:19 PM

I have an '83 300SD and, to my knowledge, there isn't any type of reserve that requires flipping a switch to activate. Therefore, the 12 L reserve that your shop manual mentions is most likely just factored in to the overall capacity of the tank. I feel fairly certain that the low-fuel indicator light coming on is what they mean by stating that it has a reserve. The 12 Liters for the reserve sounds about right since my low-fuel light comes on when the needle gets slightly below the 1/4 tank mark. At 77 Liters, 1/4 of a tank would be 19.25 liters so a 12 liter reserve would make sense. If I were at home I might be able to confirm since my manuals are all there. One other thing that leads me to believe your suspicions are correct is that if the 12 liters were in addition to the 77, that would mean an 89 liter tank or 23.51 gallons. That would cost me over $30 to fill up and I don't recall ever spending more than $23 or $24 to fill up. By the way, your fuel mileage seems to be pretty good.

P.E.Haiges · #3 09-18-2002, 05:01 PM

My '87 300SDL manual says 90 l (23.8 gal.) with a 12.5 l (3.3 gal.) reserve. I don't know if this is the same tank as your car has.

However, I was always able to put about a gallon more than the manual said in my '80 300SD. It would take 25 gallons when completely empty.

P E H

psfred · #4 09-18-2002, 10:23 PM

23 gal. seems about right -- these things have a driving range of 700 miles or more -- quite a long time to sit in the seat!

My 72 280 has a 25 gal tank, but believe me, it ain't gonna go any 600 miles before fillup time!

Peter

#5 09-19-2002, 03:31 PM

I finally got a chance to check my '83 owners manual and it says 77 liters "including a reserve of 12.5 l". So, seems like the final word is 20.3 gallons, at least on this 126 bodied 300SD. I'm sure you can probably get a little more in if you run the fuel all the way up the filler neck but the manual emphatically states not to continue fueling past the first time the nozzle shuts itself off. So it looks like your cruising range is about 522 miles at 25.74 mpg. I'd suggest you start looking for a diesel pump at about 475 to 500 miles though, just in case.