300 SD or SDL - Which is Better, and Why? - Page 2 - PeachParts Mercedes-Benz Forum

Ken300D · #16 06-12-2002, 10:07 PM

I feel fortunate (so far) to have direct experience with both of these engines, the 5-cyl series and the 6-cyl series - but in the smaller 300D cars.

They are different animals, but both are quite reliable if cared for. I have the impression that the 5-cyl is tougher and longer lasting, but nothing to base that on except the iron head vs. the aluminum one in the 6-cyl. You really don't want to let the 6-cyl engine ever overheat.

The 6-cyl is a more powerful engine and seems to have more top-end power on the highway. Some of it is the gearing of the drivetrain, since the 5-cyl is turning over faster for a given highway speed. The 5-cyl also seems louder.

Because of the difference in gearing, the 6-cyl is not getting much turbo boost at 55-60 mph, and fuel mileage is incredible at these speeds.

If I could have my pick, I'd choose the '87 SDL.

But I really love driving the '82 300D. You know you're driving a MACHINE when you're cruising......

I pity the fool that runs into me with a Celica, Escort, Sentra, Yugo, etc. etc.

Ken300D

190D22 · #17 06-13-2002, 01:15 PM

I honestly don't see why everyone is so afraid of overheating... If you take car of the cooling system then you shouldn't worry about it. I would take the newer SDL because of improvements throughout the whole car. It would make sense that it is a smoother riding car and more comfortable due to it being newer.

I say, get which one feels better to you. There is no 'better' car. Something in one outweighs something in the other. There's always a tradeoff somewhere. My car is small and gets great mileage. But I have no passenger and cargo room. Your beasts are huge and can fit a circus in it. But you loose that in mileage. Always a tradeoff.

psfred · #18 06-14-2002, 09:01 PM

Aluminum radiator plus plastic tanks plus green coolant = corrosion and brittle tank nipples = sudden and severe overheating with the 601/602/603 engines. Probably not anticipated by the engineers, but if that upper radiator hose pops off on the highway, kiss the head bye-bye. Happened to my sister last summer with her 92 Volvo 740 Turbo -- had to find a reman head on short order!

Peter

190D22 · #19 06-16-2002, 05:53 PM

See that's what I am saying. If you take care of your cooling system, have it checked out often you won't have to worry about the system dying. Who uses the green coolant here? Mine had the orange stuff in it when I got it and mercedes (after they replaced my radiator w/ a new one and my aux coolant pump) put in the orange stuff.

My point is if you take proper care of your car, aluminum head or iron, it will last. Hell you could make a hyundai last a long time with proper care. But I wouldn't waste my money on that ****.