Whenever someone suggests "Rotella" it means they're a WalMart shopper.

Why not go to the source?

http://www.startekinfo.com/StarTek/outside/9511/?requestedDocId=9511

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

Be excellent if you bothered to read the container on Rotella. It meets the CJ-4 spec for diesels. Your cited M/B recommendation shows the older CG-4 spec.

What does Rotella have to do with "Wal-Mart"? It's available at many retail outlets.

I think he was trying to be snide on the sly as he has been with owners of old MBs in the past, but it appears it's backfired on him yet again. There is a MB approved oil available at Wal-Mart, namely the 5W-40 weight Mobil 1, so I don't see what's wrong with being a Wal-Mart shopper.

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'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.

Most ALL truck stops sell Rotella! I buy mine a NAPA! And actually Lkchris MB is not the source . . . some refiner produces the oil for them and puts the nice little label on for them too!

A synthetic oil will flow better at colder temps . . . obviously switching to a 5W from a 10W also will help in cold weather, make sure you use Diesel compatible oil.

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82 240D Manual 277K and still rolling!
02 Volvo S60 AWD For Sale

most of these oil threads get heated, and/or snide and snobby. this one got even worse, and quickly.

5w-40 in the cold weather, to answer the original question. i guess where you buy it now kicks you out of the cool kids club.

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1985 300D - 1984 Euro 280E AMG Clone (SOLD) - 1978 280CE (SOLD) - 1983 300D (SOLD) - 1981 300D (SOLD)

I use distilled water. It has a great cleaning ability.

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-Typos courtesy of my mobile phone.

And fantastic lubricative properties.

On a serious note though, I put in 15W40 this summer and I'm not due for a change til february. I'm in the same climate as the OP, should I change it now, or can I tough it through?

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1983 240D 3.0T 4-speed manual, now sold

1989 Subaru GL Wagon 5-speed Touring Edition

I'm with Brian - use 5w-40 all year, then you never have to think about when the change or leave it.

Plus, if you leave a thicker oil in b/c you just don't want to change it, it might make for some hard starts on those cold Massachusetts mornings...

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1984 300D: 275,000 miles (soon to be for sale)

In search of my 1987 300D in anything but white.

If it were me I would change it. It will start much easier in weather below freezing.

Another user on here tried to make it through his first winter here in MN with dino oil.
It wouldn't start at 4F. He switched to synthetic the next winter and cold started it near -20F.

Not only does it make a difference in how cold the car will start in, it provides better protection for the engine since it flows better right away when the engine starts turning.

I too run 5w-40 all year. I used to run M1 but they raised the prices and now it is about $7+ difference a gallon around here so last spring I switched to Rotella.

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2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD