Mile per galon for 300 Turbo Diesel's - PeachParts Mercedes-Benz Forum

#1 02-25-2003, 12:57 PM

I have done this before and asked you all questions about my 240 D,.....I would like to up grad to a 1983 300-D Turbo Diesl.
I have found a real nice 300-D at a repo lot and I can get it at a good price, with leather seat, Auto transmision,..the paint is good and it seem not to smoke blue smoke at all,...runs real good.
What I need to know is what kind of milage will I get or what milage does anyone else get with theres ?

My 1978 300-D is not getting any milage at all anymore, could I do something to make it any beter ?,........of course this car is gitting old and has about 378000 on it but still run's Ok.

Rushman

JHZR2 · #2 02-25-2003, 02:24 PM

I only drive mixed or highway only miles. In mixed driving, Ill get 26-27, and highway only, ill get 27-28, but as high as 30...
This is using dino 15w-40 diesel oil (I havent gotten any better MPG using delvac1 synth), and truck stop diesel with a splash of diesel fuel additive (watch out adding it, I find that my car will drop in MPG by 1-2 if I add too much and use it a few tanks in a row... I think it starts to dilute the fuel slowly, and it is usally a kerosene base, which I guess isnt as good for running...

JMH

rickg · #3 02-25-2003, 02:25 PM

Go here:
what kind of mpg are you getting?

mechmagcn · #4 02-25-2003, 06:05 PM

On my first road trip with my 81 300SD, I got 27.5 MPG. This was mostly highway miles, 65-75 MPH. Was impressed, seeing as diesel was $179.9 in So. Louisiana.
Jeff

lorenztl · #5 02-26-2003, 11:05 PM

My 84 300D with 219,000 gets 21.5 - 24.5 mpg using 15W-40 Majestic. It could be several mpg higher with a lock up converter and taller 4th gear in the auto tranny. At 70mph it revs at 3300rpm which of course detrimental to economy for a diesel. Most gassers get better than this. It's a great automobile otherwise though! Enjoy, Tom

jjalex · #6 03-02-2003, 05:31 PM

My '84 300D gets 23-24mpg. I usually commute on the Interstate at 70-75mph. I use Rotella Syn now, but will switch to Rotella Dino 15W40 as soon as it warms up a bit here in Wisconsin....

artpb · #7 03-02-2003, 05:47 PM

My 1983 300SD gets 27mpg on the highway at 70mph with just the driver in it and 23.5 combined with a load of 5 people and a full trunk. From what I've seen this is pretty much average performence.

diesel don · #8 03-02-2003, 08:21 PM

24-26 mpg

Don

gsxr · #9 03-03-2003, 03:37 PM

Like I said in the thread that Rick posted, there was a VERY VERY long thread about this a while ago, try to find it in the search feature. Basically there is a huge range of MPG achieved by different cars of the same model/year (assuming 82-85 300D, W123.133). The low end seems to be 18-22 in town and 22-24 freeway, the high end is 24-26 in town and 28-32 freeway. California diesel fuel produces 10-15% lower MPG and I have documented this over thousands of miles on my cars (I lived in CA for 8 years, now I'm in ID).

Why do some get such crappy mileage? Well, after chasing down ALL the normal possibilities (dragging brakes, tire pressure, clogged filters, IP timing, valve adjustment, chain stretch, you name it) the final culprit ends up being an injection pump out of calibration. But most folks choose to live with it rather than spend $$$ to pull the pump & recalibrate it, or install a rebuilt.

Regards,