Expected MPG for OM617 engine - PeachParts Mercedes-Benz Forum

Tanksowner · #1 12-22-2010, 09:35 PM

So my fuel gauge has been jumpy and unreliable lately. Until I can get it fixed, I've filled up my tank with fuel and reset the trip odometer. What can I expect for miles per gallon/how many miles I'll end up with on the trip odometer before I need to fill up again?

kerry · #2 12-22-2010, 09:50 PM

23-25mpg. Or, if you believe Craigslist and Ebay, 35mpg

PhantomCadillac · #3 12-22-2010, 09:53 PM

Play it safe and fill up after you go 300 miles. But I hate to go below a 1/4 tank.

whunter · #4 12-22-2010, 09:55 PM

Quote:

Originally Posted by Tanksowner

So my fuel gauge has been jumpy and unreliable lately.

Fuel Tank Light
Fuel Tank Light

Fuel Gauge and Sending Unit threads
Fuel Gauge and Sending Unit threads

Fuel Sender 85 300D- Cleaned (Pics)
Fuel Sender 85 300D- Cleaned (Pics)

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Tanksowner · #5 12-22-2010, 10:27 PM

Thank you guys for the info. Again, I do appreciate how easy it is to access these parts for maintenance.

To be honest, I initially did believe my MPG would be that high. Wishful thinking, I guess. But 28 MPG isn't any slouch number, especially considering the car it's going with. I can deal with 26-28 MPG, it's slightly higher than what I've gotten out of my Intrepid with the 2.7 engine.

TylerH860 · #6 12-22-2010, 10:40 PM

With my '85 it would hit empty at about 350 miles.

Stretch · #7 12-23-2010, 04:02 AM

With mixed driving in my W123 (0 mph => 80 mph) I used to get a steady 10km per litre on a slightly worn out engine. That's about 25 mpg (US)

{Non turbo OM617 - automatic gearbox - standard diff - 195/70r14s}

I hope for more when the engine rebuild is done

mlozzi200478 · #8 12-23-2010, 06:05 AM

well first off i would diagnose the jumpy fuel gauge issue,it sounds to me like something a defective ovp would do thats overload voltage regulator,its located behind the removeable plastic panel behind the battery,secondary id shoot at about 25-28 miles per gallon,goodluck.marc my 3.0L naturally asp. gets 300 miles per 18 gallon tank.i dont know if thats good or bad.lol!!!

oldsinner111 · #9 12-23-2010, 06:27 AM

If you live in rural area and drive 60 mph 32 is within reach constantly.

layback40 · #10 12-23-2010, 06:41 AM

Quote:

Originally Posted by oldsinner111

If you live in rural area and drive 60 mph 32 is within reach constantly.

This is about what I have got in my 2 n/a's over the years.
Best I have done is about 37 at 50 mph..
Once you get over 70 mph it drops a lot.
When new, i used to get about 35 at 60 mph in the 1980.

Tanksowner · #11 12-23-2010, 01:07 PM

Quote:

Originally Posted by oldsinner111

If you live in rural area and drive 60 mph 32 is within reach constantly.

Where I live, it's mostly rural highway, and I travel anywhere from 40-60 mph on a given daily commute. My commute is short (about 8 miles). I might even be able to go over a month before I have to fill up?

barry123400 · #12 12-23-2010, 01:27 PM

Quote:

Originally Posted by Tanksowner

Where I live, it's mostly rural highway, and I travel anywhere from 40-60 mph on a given daily commute. My commute is short (about 8 miles). I might even be able to go over a month before I have to fill up?

Use of synthetic oil should help mpg with those short commute trips. I guess one would have to trade off cost of the synthetic versus fuel savings.

When those engines are cold the engines oil drag is very signifigant. Easier starting might enter the picture as well though.

pawoSD · #13 12-23-2010, 01:36 PM

Quote:

Originally Posted by TylerH860

With my '85 it would hit empty at about 350 miles.

Thats way early....I regularly go over 400-425 before I even come close to needing fuel. Usually about 3-4 gallons left in the tank if I fill at 425.

Avg mpg I get is about 23-24 as I drive granny style now that diesel costs a ton.

thayer · #14 12-23-2010, 02:35 PM

This may be because I drive mostly highway and never use the brakes...but I typically get about 27mp....I broke 30mpg ONE time, going 55, across highway 58 along southern virginia from Mt. Aity NC to Williamsburg. I was rarely out of 4th gear and never touched the brakes....."Never is relative...most stops I was able to allow that 3.07 differential to do the braking"

I have run out of fuel Once.....I was at 503 miles on the odometer.

pawoSD · #15 12-23-2010, 03:01 PM

I ran out of fuel on the way home from buying the car, with 514 on the trip odo.