My mileage sucks!

[mobenz]

1978 300 CD, approximately 120K. Runs like a charm. Starts great. But I am only able to squeeze about 23-25 MPG out of it, with 70% if the driving being highway miles. Good tires, properly inflated. Good alignment. Fresh filters for oil and fuel. New injectors within the last 5000 miles. What am I missing, or is this as good as it gets? Had a 1980 240D once that couldn't seem to drop below 31 MPG. Any suggestions appreciated.

23-25 is 100% normal.

[barry123400]

The non turbocharged engine is a little less efficient in many peoples opinion. I own a non turbo 77 and also agree. Your milage sounds normal. Even perhaps the higher side of normal.
Also remember you have a higher ratio rear end under that car versus the turbo versions. Going to make some difference as well.

[Hatterasguy]

Contrary to what they post on ebay...thats about right.

Check your timing, make sure it is correct. I'm assuming you have all the basics covered like the valves and filters etc.

[barry123400]

[QUOTE=Hatterasguy;1499228]Contrary to what they post on ebay...thats about right.
Hatterasguy is right. As I see it there has got to be some hidden cost of ownership for a car that everyone knows goes a million miles. Most just may not want to stay aboard for the last 600 thousand of it.
It"s quite funny really that almost all the 123 cars on ebay get about 40 miles per gallon. In the next statement they almost all claim low milage.
Then again they are always the best examples made in that year in the best colour choices. Having had their oil changed every week with only the best mercedes oil. Plus having transmission fluid changed out every twenty thousand instead of the recommended thirty thousand. Of course every agragate issue has been dealt with by mercedes technicians as well. Perhaps that why they get 40 mpg

Originally Posted by barry123400

Also remember you have a higher ratio rear end under that car versus the turbo versions.

Other way 'round. He has a lower ratio than the turbo cars.