new oil thread... beware! asking for opinions

[vstech]

ok here is my idea.
synthetic oil seems to improve life on gassers and cars that have a lot of heat (i.e. air cooled engines) our MB's have a large oil cooler to combat thermal breakdown, so why are we all strongly recommending the synthetic oil? as long as it is good multi viscosity for the climate you live in, and you use ONLY diesel rated detergent grade, I am thinking Synthetic may be overkill.
I have however heard that the True synthetic multi viscosity oils use a better method for getting the temp ratings, resulting in better true viscosity (from the oil companies of course...)
what do you guys and gals think?

[F18]

John....I think the use of full synthetic in a current MB Diesel is overkill....and over priced. I use a blend of syn and dino in the winter just to improve flow characteristics in very cold weather. But warm weather driving is 15w40 dino all the way with 5,000mi oil and filter changes. All my previous diesels ran on the dino oil into the hundreds of thousands of miles with no internal problems...no coked up injectors....and very little variance or drop in compression.

These diesel engines are so efficient in managing heat that I could not imagine that any quality oil (either dino or syn) would suffer from heat degredation over the proper change interval. The weak link is the filter....the oil will outlast the filter...they start to clog with carbon as soon as you turn the key. You probably benefit more from an intermediate filter change (which I have done) than changing oil too frequently, like 2K to 3K miles or using full synthetic.
I am no expert, all I know is from my experience with my four diesels......

[Brian Carlton]

I look at it this way:

The Rotella Syn runs to 6K with tolerable soot (less than 1%). That doubles the usual dino interval. The Rotella costs $16. per gallon, roughly double the cost of the dino.

So, I save myself the cost of a filter and the labor to do the change.

Additionally, I get the benefits of significantly improved cold weather starting capability.

[TheDon]

I want to try this synthetic stuff.. but my wallet never allows it

[300SD81]

I use the Mobile 1 TurboDiesel oil, I like overkill, engines are expensive.. but I don't think I'll be able to afford it when its time for the next change in a month or so.. Anyone know a quality, cheap oil for summer use?

[F18]

Originally Posted by 300SD81

I use the Mobile 1 TurboDiesel oil, I like overkill, engines are expensive.. but I don't think I'll be able to afford it when its time for the next change in a month or so.. Anyone know a quality, cheap oil for summer use?

Rotella 15W40....its available everywhere including Walmart.

[speedy82]

Natural oil can shear and with the intense heat of a diesel engine, I just don't trust it. All my boys run on synthetic.

[probear]

I stick with synthetic if not for the turbo alone.........That is the major heat source that the oil has to deal with.
Just think, when you shut down your engine, the turbo is still spinning several thousand rpms with no oil flow........

Synthetic just lasts longer....and lubes better.

[NC Benz]

Originally Posted by probear

I stick with synthetic if not for the turbo alone.........That is the major heat source that the oil has to deal with.
Just think, when you shut down your engine, the turbo is still spinning several thousand rpms with no oil flow........

Synthetic just lasts longer....and lubes better.

Hence the reason I let it idle for a little while to let the turbo "unwind".

[F18]

You know....if someone could show me a real/true cost benefit of running syn in my diesels long term I would bite. But all I have read and heard is Oil Company propaganda. Does it mean my vehicles would go for an additional 50K.....500K instead of 449K if I use synthetic, but at what cost? The rest of the car would be falling apart! They already outlast 2 gasoline vehicles without even trying...........

[BioPOWER]

My Mercedes runs Rotella dino 15W40, I've never had a problem with it.
My Excursion runs whatever they have at the Walmart quick-lube, friggin' thing takes a boatload of oil.
Don't even get me started on the TDI's Castrol synthetic 505.01, VW special.

The way I look at it, oil is oil, and as long as it meets the manufacturer's specs, your engine will be fine.

[BioPOWER]

On another note, somewhat relating to synthetic vs. dino oil.....
When I first got into biodiesel, I produced it myself in a 40gal processor. Naturally, quality varied, and some batches were much better than others. The "good" batches fueled the Mercedes, while the somewhat crappy batches went to the Excursion (7.3 Powerstroke). Looking back on it, I realize the Powerstroke's electronic unit injection system is much more precise than the Mercedes's IP-and-nozzles system. The bad fuel should've gone to the Mercedes, and the Powerstroke should've had the good fuel. Today, both cars run perfectly.

My point is, it's not going to make a huge difference whether you use synthetic or dino. The crappy biodiesel did not affect my Excursion any more than the good biodiesel affected my Mercedes. Over the lifetime of your vehicle, it will not make a big difference whether you use synthetic or dino. Synthetic is for high-tolerance gassers and TDIs, while dino is all our old, "loose" Mercedes diesels need.

Have there been any documented incidents of failure in a Mercedes diesel from not using the right oil? No. It is a different story with PD-TDIs, which have had documented failures of valve lifters and cam bearings, resulting from not using 505.01-spec synthetic oils.

[Hatterasguy]

You have to use synthetic in the CDI's...

Also if your older MB has FSS and you plan on following it you need to use synthetic.

[radunegru]

Just few words guys about synthetic.
I an sold for life to it.
Never use anything else but Mobil 1 15w50 expended performance in all my cars. My last Mercedes( 300E 2.8) had it for the last 120k at a 15k interval. It was not burning or loosing not even an ounce.
Now that I got my new baby E300 96 with 606912 I treat him the best ....Mobil1 ESP formula M 5W40.
I got it for $6 a quart (thanks to Phill) and I am going to change it every 10K. My dad that lives in Europe is using the same oil on his 270CDI but the change interval is 30000KM.
Maybe in this country the oil companies wants to hook us up to the 3000 change interval to maximize their profits.

I use synthetic with a 5000 mile interval, which is probably overkill. I could probably get away with dino oil for 5000 miles (but I really wouldn't want to). However, the price difference isn't that great. At this point, the cost of an oil change isn't much more than filling the tank with diesel. Regardless of the long term benefits, the most noticeable advantage is cold weather starting. With 5W40 the car starts much easier than with 15W40.