I get 17mpg

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

I own an .82 automatic 240D that gets about 22 mpg city and at best, 24 highway. At least to reduce the racket at highway speeds, I would consider a 3.47 diff-swap, but nothing more radical. I may be able to try this, as I've been offered a free 80 300D with a bad tranny. Will post further if it happens.

Happy Motoring, Mark

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DrDKW

In a car with big displacement and lots of torque, a taller rear wouldn't hurt you as much. A Vette can handle 1200 rpms in 6th gear because it has 6.0tlrs of torque. Your 69hp 240D can't. You might have a top speed of 65 mph if you go with a taller rear. If anything, as a previous poster suggested, try taller tires. If you're running 195,70R14's, try a 195/75R14 or a 205/70. If you're running 205/70's, try 205/75s.

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Sharing my partner's 2012 Forte 5dr SX til I find my next 123 or 126..
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Do I miss being a service advisor ???

I think you can probably get away with this with an automatic, but your acceleration getting up to highway speed will be glacial. Look out for the semis running you down on the on ramp!

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

A 3.46 would be the best option. It will not hurt acceleration as much as a 3.07 or 2.88.

gee I know someone with a complete 4 speed for a W123.. he might be selling.. since his time machine needs a new fuel pump

wow... that sucks.. I'm getting 24mpg with my 300D turbo

turbo.. turbo... turbo

turbo
turbo


thats fun to say


turbo


tuuurrrrbooooooo

As my automatic 240D seems to rev higher in the various gears than my stickshift version (probably due to the inherent slippage in the torque-converter), I felt that with the 3.46 the tranny could compensate for some of the lost acceleration by hanging in the lower gears a bit longer.

Interesingly, for those wondering what axle ratios the factory intended for some of the different tranny options, while I don't have data for the 240D, one of my reference books gives the rear-end ratio for a mid '70s Euro 4-speed W114 230-6 as 3.46, but 3.92 for the same car with a 5-speed.

Happy Motoring, Mark

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DrDKW

3.92- 200D, 220D, 200/200T
3.69- 240D/TD, 230E/CE/TE
3.58- 280E/CE/TE, 250/250T
3.46- 300D/CD/TD non-turbo
3.07- 300D/CD/TD/SD Turbo
2.88- 300D/CD/TD/SD Turbo, 85 only.

500ft pounds vs what about 70? In cars that have a pretty similer weight.

Maybe in a flat part of the country but around here we have hills, some are pretty steep. I would imagin a stock 240D would have trouble with some of them. Throw a high rear in the thing and you will be in 3rd or 2nd with your foot to the floor trying not to get rear ended.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

It seems as if my automatic 240D first-gear is like a granny-low, but the engine runs out of steam in third, while trying to accelerate uphill at around 40 - 45 mph. In theory, with the proper rear-end ratio, I could take local hills in second, while third gear could provide the same freeway uphill performance that 4th does now, and 4th would serve as overdrive for flat and downhill use. But I don't know if running the automatic like that would be harmfull. In any case I may decide against the diff change as the 240D serves ideally for most of my local driving, while my Nissan is the primary long-distance car, and returns 30 - 35 highway mpg.

Happy Motoring, Mark

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DrDKW

I don't think that will hurt the tranny. For a little more money though a stick transplant might be a better overall choice.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Well, the 3.46 diff would be free and a much more simple swap than a tranny conversion, and the cheapest stick 240D parts-car I've seen in the past year was $350, for a very rusty 300+ mile example. Of course if I could find a suitable parts-car with a 5-speed....

Happy Motoring, Mark

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DrDKW

Toms advice is probably pretty accurate. He has driven enough 240ds over the years.
That said I would check your injectors out as they could be the original units untouched all these years. . Also the pump timing and chain stretch. You really want every last horseower potentially available. I even feel this way about my 240ds with standards when I get a chance to use them.

BTW, it's 3.07 not 3.08.

I wouldn't put taller gears in a 240D if you ever need to drive up hills.