what kind of oil?
 

what kind of oil should i use for my 87 300DT i wanna do a oil change i usually use lubor molly but this time i wanna change and go with something new. any idea guys?

Mobil-1 synthetic oil in a 5W-40 weight with a "CF" or "CH" rating is the preferred choice for that engine.

I personally use Rotella-syn due to cost and the shorter change interval (5K), but, it's not as good as the Mobil-1.

and how many quarts about 8? and what about that shell rotella super shoot or something like that? any good?

Start with 7 quarts and check it again after you drive it.

Don't know of "Shell Rotella Super Shoot".

Synth vs petrol
 

I purchased my 1987 300TD about a month ago. Previous owner used regular oil. Is there any problem with switching to synthetic oil? Am I going to have leaks all over the place? What are the issues related to switching from non-synth to synthetic oil?

I don't belive there are any oil leak issues anymore
 

the leaks mostly came from aromatics differances in the past.
most oil companies have solved the leakage issues with the modern synthetics.
I vote for Mobil 1 5W40 Diesel or SUV/Truck oil. and Fram turkey filters
John

So I should go ahead and switch to Mobil 1 or Amsoil?
 

So, I should go ahead and switch to Mobil 1 or Amsoil? Does anyone know which is a better Synth oil? What other choices are there?

I'm sure either one will do a fine job for you. Mobil-1 is a bit less costly AFAIK and is easier to obtain.

shell rotella synthetic isnt as good as mobil 1 5w40 as its a group 3 hydrocracked synthetic blend. So in comparison mobil 1 5w40 is a group 5 if im not mistaken and is a full synthetic so its the best you can get. Not to say the rotella is bad its just not as good, but much easier to obtain (local walmart stocks it) compared to mobil 1 5w40.

Mobil 1 15w50 is also a good alternative choice and ive found to be readily available even at target's. Amsoil 15w40 synthetic and 5w40 synthetics are also group 5's and are at the same level as the mobil 1 so you can go with that if you have a amsoil supplier near you that has those in stock.

Other choices are german synthetics like ELF and Pentosin. Both make 5w40 diesel rated synthetics that are pretty good but some of pentosin's oils are group 3 oils so they arent full synthetics but blends.

Valvoline 15W40
 

Personally, I like the additive package in the Valvoline line. It seems to have the best detergent qualities. It's all I've ever used and every Valvoline engine I've had apart in different degrees was clean enough to eat off of inside. Mobile One makes my engines leak but I believe it works excellent for sub zero start up and Rotilla-T, while and excellent product, doesn't seem to keep the engine near as clean inside as the Valvoline products. The Valvoline Premium Blue and Premium Blue Extreme 15W40 is their best diesel product. http://www.valvoline.com/premiumblue/

You live in California by the looks of your post, Synthetics are nice in the cold weather for start up protection, but for the money, the advantages are questionable if you are changing oil every 3-5K anyway and operating in above freezing temps all the time. The most important aspect is to ensure the oil you choose is API Diesel rated CI-4 Plus, CI-4, CH-4, SL--(gasoline rating) is not important. The engine is 20 years old, ensuring a API diesel rating is the most important factor.

Your owners manual outlines oil change qualities, the 603 requires 8 Liters with a filter and 7.5L without. 8 Liters is equal to 8.45 quarts.

IMHO, there is such a contaminate load in the oil of a diesel to start with I would have a tough time leaving it in place for the miles the oil manufactures would like. Browse this link on Motorcycle oils. It's fascinating. Yes I know it's not an MB diesel article, but I think it reveals some very interesting data concerning viscosity retention. Kind of an eye opener.

http://www.xs11.com/stories/mcnoil94.htm

For synthetic, use Mobil Delvac-I for diesel or Delo Synthetic, both are CI-4+ rated which is far higher than gas specific Mobil-I regular.

As far as best oil goes, check out the various UOA in Bob Is The Oil Guy forum at http://theoildrop.server101.com/cgi/ultimatebb.cgi

You will be pleasently surprised how well group-II HDEO diesel oil like Delo 400 does against synthetic diesel oils, also Mobil's own Delvac MX which is group I with additives too manages fantastic results. Unless facing extremely low temperatures, using a group II oil like Delo 400 or even Delvac Super/MX changed at intervals of 5000 miles makes good economic sense and it provides excellent protection as well.

Hmm... not going to start a war about oil filters, but I'd take a look at this thread.
http://mbca.cartama.net/showthread.php?t=15666&page=1&pp=15

My 300D seems to like Shell Rotella 15w-30, non-synthetic(white bottle).

Isn't Rotella a 15w-40 oil?