Oil Weight
 

Is 15W40 light enough for single digit temperatures?

That's what I run, and mine have never had problems at single digits without the block heater.

Yep, but you'll notice it during cold starts (won't crank as quickly). I know some of our colder climated members go a shade thinner in winter to help with cold starts.

YAY! OIL THREAD


Haven't read about anyone switching to synthetic that wasn't happier with the start speed. I have been through two winters with 15w40 and if it got below say, 20 degrees, and I didn't plug the block heater in, I had difficulty starting.

BUT!

I had electrical problems leading to low battery most of the time. Couldn't handle it.

I bet now, with all those electrical problems gone, it would start fine on 15w40.

I don't know though, cuz I switched to synthetic, its the same price if you add in the extended drain interval.

15W-40 is good down to 5 degrees. Information was pulled from the factory owners manual.

oil and the cold BRRRRRRR
 

I run 5-40 mobile 1 in mine. It started today at 2F sitting outside and not plugged in.

Of course the drifting snow wouldn't let me out, but it did start.

Jon J
240D

NOT to loose my smart @$$ reputation
 

"light enough" depends on how much you are trying to pick up!! :D

But just to confirm, what kind of engine(s) and single digit Fahrenheit, right? When in doubt, I defer to the directions. Rest assured, the Germans did NOT put any guesswork into things like that. I use 5-40 synthetic for the the benefit of quieter lifters, the slightly extended drain interval and easier starting (3 bad glow plugs and started at 35 degrees) are a good side effect.

Hey Joe,
When all else fails, read the instructions! :rolleyes:

For others that may not understand;

Thats the little book that should be in the glove box.

Attached is the relevant page.

You may notice that 15w40 is good down to +23F
10w is good for -4F

Given that every car had an owners book when new, I often wonder where they have all gone.

Thanks for the responses. I apologize for bothering you as I should have done some research on my own. I was kind of looking for personal experience with modern oils as opposed to information that was written almost 30 years ago.

I will read the instructions next time as opposed to bothering you fine folks with a dumb question.

They are for sale on ebay - probably never to be sold!

I don't think it is a dumb question - you will find similar threads on this topic on this forum. Recently there was a thread (or a post was it? - I forget sorry) urging people to use synthetic oil.

You can also find loads of information on manufacturers' web sites - probably too much information!

Joe,
There is no such thing as a dumb question. :)

Modern oils are still graded the same as they were 30 years ago for viscosity.
While we have advanced a little from the specifications of many years ago, moving from CC to CJ or better, each change tends to be just an additional requirement, not a new specification. It is a myth that in moving to a "more modern oil" one should change the viscosity of the oil. The viscosity requirement is part of the design requirements of the lubrication system as well as component design such as bearings. Small changes are unlikely to have a catastrophic effect as lube system design is normally substantial over design.
My posting the page was to make sure that people know what MB required. It definitely was not aimed at you! Unfortunately many never read instruction books. Just watch kids opening presents. I am sure you are not a kid though!! The last thing they look at is the instructions. They normally get thrown out with the wrapping.

There you go Army, I would like to get my hands on an owners book (not shop manual), hard copy, for a 1987 250 TD .
Let me know if you find one.

I guess you want it in English? German would probably be an easy find! I'll see what I can do...

Although an automotive purist, I wish I'd of kept the pricelist window stickers AND owners manuals from all the cars I've owned. Especially the window pricelist sticker from my '83 300SD and it's owners manual. The worthless, ungrateful doofus that bought the car from me when I bought a new MB diesel 12 years ago, could not have cared less about how he was going to treat the SD after acquiring it from me.:(