Gas Mileage and Sythetics? - PeachParts Mercedes-Benz Forum

#1 11-19-2001, 09:38 PM

I recently purchased a 1992 300D 2.5. I have been getting about 35mpg highway. Is this reasonable?

I drive 50-60K a year and want to make sure I am doing all I can to maximize my fuel economy. A few questions:

- Are these engines to have their valves adjusted?

- Are there performance chips for these diesels on the market that have shown increased efficiency?

- I have had a lot of luck with synthetic lubricants before. What are your experiences with a change from mineral to synthetic all around at 136K. My primary concern are leaks developing.

- What else can be done to increase fuel efficiency?

truth

rbauman · #2 11-20-2001, 01:01 PM

Truth, The techniques in driving and servicing your Benz are important to the longevity of the auto as well as the wear and tear. Drive in the 50-65 mph area with gentle throttle, modern synthetic lubricants and consistent servicing of the engine and drive train: you will obtain the best mileage. The amount you deviate from these procedures will decrease your mileage. Is this the answer you're looking for? Roger
P. S. Tire rolling resistance and other minor factors have some influence.

P.E.Haiges · #3 11-20-2001, 07:13 PM

I put Castrol Syntec in a '79 300SD I bought at 160,000 miles and the leaks stopped and now 36,000 miles lates it uses one quart per 10,000 instead of the 3 quarts per 10,000 miles it used when I got it. Yes, I change the oil at 10,000 milles because no one has proved to me that changing the oil more often is necessary for my type of driving. ~~~~~~~~~~~~~~~~~~~~~~~PEH~~~~~~~~~~~~~~~~~~~~~~~~~

psfred · #4 11-20-2001, 09:43 PM

35 mpg isn't bad -- I get 30 mixed highway/city in my 87 300D.

I changed to synthetic at 166,000 miles -- no oil comsumption before or after (mobil 1 15W50).

Driving technique has a lot to do with milage -- I'd probably do better if I could keep my foot out of the 300!

Peter