Max temp for SAE 30 in a diesel

[troyb43]

How about the Amsoil ACD for this application?

Synthetic SAE 10W-30/SAE 30 Heavy-Duty Motor Oil

Exceeds both 10W-30 multi-grade and SAE 30 straight-grade viscosity requirements. Provides outstanding performance in pre-2007 diesel engines in on-road applications as well as all model-year diesel engines in off-road apps. Also recommended for gasoline engines requiring API SL or previous specifications.

 

[Doug Hillary]

Hi,
troyb43 - Please read the OP. It certainly does not mention the product you suggest and is about "technical" matters concerning a specific SAE30 monograde lubricant

 

[troyb43]

Originally Posted By: Doug Hillary
Hi,
troyb43 - Please read the OP. It certainly does not mention the product you suggest and is about "technical" matters concerning a specific SAE30 monograde lubricant

Sorry the use of Amsoil offended you Doug

 

[Doug Hillary]

Hi,
troyb43 - No offense taken!

 

[JHZR2]

Doug is correct. I'm not looking for lube recommendations, rather the theory behind why/when an sae40 is selected per the MB guidelines...

 

[ForcedInduction]

Originally Posted By: Chris142
Your underpowered MB Diesel won't work the oil enough to matter.


Thats a very ignorant statement.
The engine is cooled primarily by the engine oil, especially the pistons.

JHZR2, use synthetic. There is zero benefit to using dino oils, especially obsolete mono grades.

 

[Doug Hillary]

Hi,
ForcedInduction - Please read JHZR2's original Post, some of the answers will then make sense

 

[bullwinkle]

Originally Posted By: ForcedInduction
Originally Posted By: Chris142
Your underpowered MB Diesel won't work the oil enough to matter.


Thats a very ignorant statement.
The engine is cooled primarily by the engine oil, especially the pistons.

JHZR2, use synthetic. There is zero benefit to using dino oils, especially obsolete mono grades.
Except for the SLIGHTLY lower price! How is a monograde obsolete, anyway?

 

[bullwinkle]

I am a bit biased, as well, because my '82 has a lot of blowby and therefore leaks from pretty much everywhere, therefore I only run synthetic in it in winter, and top off with straight 30 or 15W40 in summer, when cranking speed isn't as critical to get it started. If it was a tight, leak-free motor I would probably run TDT or T6 in it year-round.

 

[JHZR2]

Again, not looking for lube recommendations. This was a theory question based upon how MB specified viscosity choices in their OM and FSMs.

I run 5w-40 year round and aren't currently inclined to change. If I do, I'll go between the three multigrades on the rotella shelf at wm.

 

[fdcg27]

Originally Posted By: ForcedInduction
Originally Posted By: Chris142
Your underpowered MB Diesel won't work the oil enough to matter.


Thats a very ignorant statement.
The engine is cooled primarily by the engine oil, especially the pistons.

JHZR2, use synthetic. There is zero benefit to using dino oils, especially obsolete mono grades.


It isn't such an ignorant statement, since the turbo five cylinder three liter only makes 123 bhp, or around 41 bhp/liter.
Also, the engine is not primarily cooled by oil.
There is oil spray directed to the undersides of the pistons on the factory turbo engines, but its cooling effect depends upon flow, not viscosity.
Finally, Mercedes did include an oil cooler in this installation, IIRC.
That plus the large sump capacity and generous coolant capacity and radiator area should result in reasonable oil temperatures under any circumstances.
Finally, the oil recommendations were based upon the oils available at the time.
JHZR, if you want to use a 30W as what amounts to a flush oil, I think you'd be fine.
Were it my car (and I'd love to find another good 123 diesel, or any clean 123), I'd not hesitate to use it were I so inclined.

 

[ForcedInduction]

Originally Posted By: bullwinkle
Except for the SLIGHTLY lower price!

That is only the initial purchase price. Synthetic is always cheaper in the long run.

Originally Posted By: fdcg27
Also, the engine is not primarily cooled by oil.

That is false information.