1982 300SD, is it a 3 speed or a 4speed? what is the final drive? rpm@70mph?

[AMG500SEC]

I had a 82 300Sd and I sold it to my friend, he says the car screams at 70 mph 3000+ rpm, is this normal for a SD?
TIA
Prasad

[barry_s_u]

My 1984 300SD is definitely a 4 speed auto. The big 1-2 shift (neck-jerking) followed by the much more refined 2-3 and 3-4 shifts.
Yes, indeed the motor is probably up around 3 grand at 70 mph. May even be a little higher. Doesn't really "scream" though. Very calmly and sedately cruises up to at least 95 without problem or objectionable noise. Does it get louder in the cabin as the speed goes up? Yes, of course! Does the car exhibit a lot more responsiveness to pressing on the throttle when the turbo is zinging at over 2000 rpm? You bet!

[85DRTYSTHBENZ]

maybe your friend just isnt used to driving a diesel engine car...they take a little getting used to,after you have driven gas cars all along...the rpms run much higher on diesel cars,but thats just how they work...at around 95 mph,in my car,the rpms are past 4 grand,but itll go like that all day with no problem...try doing that in a gas engine,and youll blow it sky high

[oil_burner]

The 1982 300 SD has a 4-speed auto - much like all W126 cars. The gear ratios are a bit different, however. It just seems like a 3 speed sometimes because it likes to shift to 3rd right after 2nd when the engine is not under much load.

I just wish the speedometer in mine went past 85 mph ...


Tell your friend to relax and enjoy the ride. [:D]

[Big D]

Not quite. I once drove an Opel Vectra for eleven hours, and it was continually bouncing of the rev limiter. After that I did another 3500 miles before I gave the car back (rental). It ran okay. The rev limiter was at 6000, and I was doing about 130 mph.

[Big D]

I think the big question that people are asking whether the high rpms tend to intrude into the cabin. After all W126 are supposed to be luxury cars with low motor noise.

[85DRTYSTHBENZ]

yeah,and rental being the key word there...its not your car,so it doesnt matter if it messes up driving at 130 with the engine at redline for eleven hours...hopefully you wouldnt do that in a car you owned,and wanted to keep running...and yes the engine noise does come into the cabin,they havent made a cabin yet to hold out the noise of a diesel engine running at 3000 rpms,but in return for that sacrifice you have an equally nice car that will typically outlast a gas engine merc by 100,000 miles or better...also i get remarks all the time when pulling in to a gas station to fill up on how quiet my car is,how theyve never heard a diesel purr like that,so yeah i guess it is a luxury ride with "low motor noise".

[AJSM]

I don't agree with you, 85.
European cars, specially german cars, are made to be driven all day at top speed.
I drive everyday 150 km in a Golf TDI 130 bhp, usually above 4000 rpm and above 200 km/h (130 mph?). It is 16 months old and 75000 km in it. Absolutly no problem.
Everytime I use my 280 SLC I make at least 350 km at speeds between 180/200 km/h and reving 5000/5500. It's a 22 year old car and it has no problem. It was made to be driven like this.

Jorge
'81 280 SLC

[Big D]

I think you're right. most german cars are made for speed. I have an 85 Golf (Gas) that I reved the hell out of. I can cruise at 110+ all day, and i've done so on a few occasions. I've put on 288,000 miles, and I couldn't get the engine to blow up. Mind you I carried out religious servicing with synthetics in tranny, and crankcase. I still have the car but have not driven it in a year and ahalf. It's standing in my garage.

[85DRTYSTHBENZ]

you guys are right..i never really thought about it from that perspective
[:)]