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1983 240D but looking
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22 Posts
Discussion Starter · #1 ·
I love my 1980 300D, but its not a pleasant car to drive at highway (65+ mph) speeds, because the engine is revving so high.

Were there ever any W123s that had lower gears for more pleasant high speed driving?

If not, if I decide to sell my car and look for an upgrade, what are the earliest models that had lower gears and/or overdrive?

Thanks for help on kind of a dumb question,

Brian
 

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Premium Member
W-1-2-3 Go!
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16,161 Posts
Talking about gearing:

240D had 3.69
Non turbo 300D had 3.48
Turbo 300D up to 84 had 3.07
Turbo 300D in 85 had 2.88
 

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1983 300D Turbo Diesel
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59 Posts
Is 3000 RPM at about 67 MPH about normal? I typically dont go over 65 because I do like to keep it under 3000 RPM.
 

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1981 240D
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185 Posts
I love my 1980 300D, but its not a pleasant car to drive at highway (65+ mph) speeds, because the engine is revving so high.

Were there ever any W123s that had lower gears for more pleasant high speed driving?

If not, if I decide to sell my car and look for an upgrade, what are the earliest models that had lower gears and/or overdrive?

Thanks for help on kind of a dumb question,

Brian
Brian: Let me know if you are looking to sell it (send pics). I might be interested in driving up there and taking it off your hands. (Pending final approval from my wife).
 

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1979 280CE
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6,118 Posts
If your worried about that get a 1985 300D Turbodiesel which has the 2.88 rear diff.

However your 80 300D can do 75MPH all day long as long as its maintained(ie full of oil). I would not worry about it revving high.
 

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1983 240D, 1974 240D
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501 Posts
If your worried about that get a 1985 300D Turbodiesel which has the 2.88 rear diff.

However your 80 300D can do 75MPH all day long as long as its maintained(ie full of oil). I would not worry about it revving high.
I 2nd this. I have no problem at highway speeds in my 84, I have accidentally bounced off of 85mph several times driving it, it rides and sounds great up at 75. Move to a turbo variant with a higher speed diff. Same car and ride with more power and better gearing.
 

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1985 380SE
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1,939 Posts
My 240D does just fine humming along at 65. Just remember to keep an eye on the oil.
 

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2001 Volvo V40
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2,955 Posts
ok so whats the supposed redline on these cars anyway? mine shifts at 4500 sometimes if im hard on the throttle.
The engines were designed to give maximum power at 4400 rpm. If you look at early diesel tachometers, the redline is around 4500-4600 rpm. It will go faster, until the governor starts limiting the rpm. Maximum speed unloaded is 5400 rpm (can be lower depending on model/IP). So your 4500 rpm shifts are ok. I wouldn't go above 4500 rpm for an extended period.
 

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1979 280CE
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6,118 Posts
My OM617.910 engine is governed to 4350 RPM. Im not sure about the on OM617.912. Anyone know?
 

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1983 240D 3.0T
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242 Posts
I have a friend who has an '85 with the 2.88 rear and new insulation and the thing sounds great. It's like a new car, that's how quiet it is.
 

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1981 300D Sedan
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12 Posts
I have a 1981 300D, and it feels a little high revving above 50. However, my GPS tells me my speedo reads about 4 MPH slow therefore it feels a bit high in the RPM dept. over 54 MPH. Nice to know the motor will take it- I kind of thought it would.

Dave
 

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1984 Mercedes 300D Euro Spec
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472 Posts
Just curious, what size differential would a euro 300D built in November 1984 have?
 

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1983 240D but looking
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22 Posts
Discussion Starter · #18 ·
Ok,ok, I'm convinced I'm not doing any damage, just making noise. It just seems so scary to me to hear a diesel rev so high for such long periods of time on the highway.

I'm a guy that has owned 2 Cummins diesels that redlined pretty low, and a diesel Rabbit 5-speed that scared the crap out of me also.

I guess my engine must be pretty robust, put together carefully, and balanced quite well.

Brian
 

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