Improving Fuel Economy on a 1987 Diesel
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From: SLC, UT
1987 Mercedes 300D Turbo
Improving Fuel Economy on a 1987 Diesel
I have a 1987 300D and it gets around 24-26 mpg.
I have been getting these kind of numbers for the last 18 months or so.
I used to have another 300D exactly like it, and it got around 26-28 mpg. It even had more miles on it (235000 vs. 185000), although it had a smoother transmission.
Does anyone know if there is some simple adjustment I can make to play with the fuel economy.
I use delo 400 sythetic, change the fuel filter (and diesel purge) regularly, and change the air filter regularly.
I think I remember reading something about sending more fuel to the engine in this car to make it a little faster off the line. Can you do the same thing in reverse and improve the fuel economy a little?
Any information would be appreciated.
I have been getting these kind of numbers for the last 18 months or so.
I used to have another 300D exactly like it, and it got around 26-28 mpg. It even had more miles on it (235000 vs. 185000), although it had a smoother transmission.
Does anyone know if there is some simple adjustment I can make to play with the fuel economy.
I use delo 400 sythetic, change the fuel filter (and diesel purge) regularly, and change the air filter regularly.
I think I remember reading something about sending more fuel to the engine in this car to make it a little faster off the line. Can you do the same thing in reverse and improve the fuel economy a little?
Any information would be appreciated.
Thread Starter
Almost a Member!
Joined: Jan 2003
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From: SLC, UT
1987 Mercedes 300D Turbo
no
I had the dealership change that out on my other car, but when I purchased this one it had already been done.
They actually replaced the turbo on my other car too, but I don't think that any of that really changed the fuel economy too much.
They actually replaced the turbo on my other car too, but I don't think that any of that really changed the fuel economy too much.
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Joined: Nov 2002
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From: San Jose
300TE / 300E / 300CE
Looks like you've done the basics. I assume the engine is perfectly tuned. Consider reducing any friction sources: repack all bearings and cv joints : Replace lubricants at tranny and diff.
Other mileage improvement tricks are pumping up the tires on the high side, remove unnecessary items of weight in the car, maybe add a front air dam.
I am surprised you only get as much as 28 MPG. I would expect a diesel to get significantly more than a gas motor. I can get as high as 22 MPG with a performance motor and I've heard of some getting 25 MPG. I guess the savings is mostly in the cost of fuel.
Other mileage improvement tricks are pumping up the tires on the high side, remove unnecessary items of weight in the car, maybe add a front air dam.
I am surprised you only get as much as 28 MPG. I would expect a diesel to get significantly more than a gas motor. I can get as high as 22 MPG with a performance motor and I've heard of some getting 25 MPG. I guess the savings is mostly in the cost of fuel.
Thread Starter
Almost a Member!
Joined: Jan 2003
Posts: 30
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From: SLC, UT
1987 Mercedes 300D Turbo
I was under the impression
I thought that the 300Es that were my cars same weight and same displacement got around 18-22 mpg. I think 25% mpg improvement is pretty substantial.
I was looking on fueleconomy.gov and they have my car listed as 25-30 mpg. That was about what I got in my old car, but not in this car. Maybe when I change the transmission it will get better.
BTW, the 24-26 mpg figure is what I get delivering pizzas
, but on the freeway it still barely hits 27. I would like to see an 87 300E get 25 mpg delivering pizzas....
I was looking on fueleconomy.gov and they have my car listed as 25-30 mpg. That was about what I got in my old car, but not in this car. Maybe when I change the transmission it will get better.
BTW, the 24-26 mpg figure is what I get delivering pizzas
, but on the freeway it still barely hits 27. I would like to see an 87 300E get 25 mpg delivering pizzas....
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Joined: Jan 2003
Posts: 242
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From: Canada
Mercedes 2019 AMG S63, 2015 E250 Bluetec. Previous: '18 E63S, '07 E63, '10 S550, '15 S550, '10 GL350
Plug in the block heater during the winter months. You won't have to idle and wait for it to warm up. That will save you a lot of diesel (and wear and tear) as well. And it will save you the embarrasement of others looking at you as your car makes all that noise on a cold start. I once had to explain to this lady what a diesel is after making a cold start. She came up to me and said "you really need to get your car checked out". How embarassing....
