1985 300SD - typical fuel mileage ?

[Chris_]

Hello,

what is the typical fuel mileage city/highway that can be expected in a 85 300SD ?

thanks

[vstech]

it depends on how you drive, but I was able to get an average of 29 ish in mine.

[t walgamuth]

Typically I would expect 16 to 19 around town and 22 to 25 highway for a mechanically sound car. driven moderately 55 to 60 you might hit 30 hiway occasionally.

Nice solid car.

Value depends totally on extent of rust, condition of interior and how much stuff is not functioning.

[cmbdiesel]

My SD does mostly secondary roads and back roads, with a few highway miles thrown in on occasion.

I get a pretty consistent 23-26 MPG. Mostly depends on the mix during the fuel run, and definitely on how it gets driven.
Fuel economy will be much better if you don't try to make up for the vehicles slow acceleration with increased throttle.

Best I ever achieved was right close to 30 on a complete highway run with little to no traffic.

Anyone who suggests that these cars will get over 30mpg has one for sale.

[Brian Carlton]

Originally Posted by cmbdiesel

Anyone who suggests that these cars will get over 30mpg has one for sale.

I'm going to get 31 mpg documented over four tanks after I switch to the Monarks.

[cmbdiesel]

Originally Posted by Brian Carlton

I'm going to get 31 mpg documented over four tanks after I switch to the Monarks.

Is the SD for sale??

[cirrusman]

See, I used to get 30-37 when I just bought mine, then I did a valve adjustment and a diesel purge a couple of years ago and now I'm getting 21-24. I must've done something wrong and I might just check my clearances soon... I hear it's the norm but I miss those 37 MPG days... :|

[Shortsguy1]

Originally Posted by cirrusman

See, I used to get 30-37 when I just bought mine, then I did a valve adjustment and a diesel purge a couple of years ago and now I'm getting 21-24. I must've done something wrong and I might just check my clearances soon... I hear it's the norm but I miss those 37 MPG days... :|

Is this possible? Could you have measured your initial numbers wrong? It seems so unlikely that you can reduce the fuel economy so drastically without massive plumes of soot or brake dust in your wake.

[whunter]

26 - 30 on my 300SD's.

It is variable with overall condition and maintenance.

I have local owners getting:

* 14 - 18 MPG, Extreme poor condition mechanical and corrosion, 650k miles, it will be scrapped in 2 years or less. Best guess; Restoration parts/labor $40,000.00 USD.

* 20 - 27 MPG, Low/average condition, "being DIY restored", 300k miles. Best guess; Restoration "parts" $2,800.00 USD.

* 28 - 31 MPG, Showroom condition, less than 90k miles. Potential cosmetic repairs; $150.00 USD.


.

[jimandsuzy]

At 75 I get about 25 or less, at 65 I get 27 or higher, I've never been able to drive even 1 tank at 55. These mpgs are on the same trips from MI to TX and back, about 1500 miles each way.

[tbomachines]

45-50 easy. Oh I have a 300sd for sale too XD

[pawoSD]

About 22-24 average if you are not a slow boring driver.

Slow boring driver maybe 26-28...

[Brian Carlton]

Originally Posted by whunter

26 - 30 on my 300SD's.

It is variable with overall condition and maintenance.

I have local owners getting:

* 14 - 18 MPG, Extreme poor condition mechanical and corrosion, 650k miles, it will be scrapped in 2 years or less. Best guess; Restoration parts/labor $40,000.00 USD.

* 20 - 27 MPG, Low/average condition, "being DIY restored", 300k miles. Best guess; Restoration "parts" $2,800.00 USD.

* 28 - 31 MPG, Showroom condition, less than 90k miles. Potential cosmetic repairs; $150.00 USD.


.

Actually, you do not need "showroom condition" to get 30 mpg. You simply need to to specific things that affect mileage. The SD is hardly in showroom condition and needs at least $1K of parts and labor at this moment. It suffers from a perpetual rough idle, a wheel bearing noise that I cannot pin down, a vacuum pump that needs to be replaced, and a serious pull to the left when braking despite a complete new front end two year ago. Oh, and it also will strand me permanently if I fail to turn the steering wheel 90 degrees before removing the key.

So, in summary, it's hardly in proper condition, but.............it still gets 29-30 mpg............even on the winter fuel.

[Skid Row Joe]

Originally Posted by Chris_

Hello,

what is the typical fuel mileage city/highway that can be expected in a 85 300SD ?

thanks

For the 213K that I drove my bought used, '83 300SD, I recall mpg calculations of 24 to 28 mpg in mixed hwy/cty driving summer/winter in Dallas, Texas.

Strictly hwy @ 60 - 65 mph? 30 mpg....

The timeframe was between 1991 and 1999 when I owned and drove by beloved '83 300SD - captioned in sig. picture below, in Jan. 1992, with 93K on it.

[Chris_]

Well I went to look at the SD today and it was :

a few places forward of rear wheels and frame member immediately inside of rear wheels was rust flakes starting.

terribly underpowered did not hear the turbo spooling up although reciept for new one was in the folder and visually I could see it was new ( solenoid on rf of fender was buzzing constantly I saw lines went to the egr does that solenoid enable/disable egr and turbo alternately ? )

When warm... blowby was sufficient to make the valve cover cap dance gently and when warm the engine ran rougher at idle than cold.

It had green antifreeze in it not sure if the old ones needed to have the benz OE coolant?

the fluids all looked good and were not mixing

the car drove staright but was real slow as mentioned above

any thoughts ?

thanks