OK, lemme start some trouble here . . . . . . . LOL.

Can regular multi-vis oil be used in these diesel engines? Can any damage be done by using, say, 20W50 Castrol or Valvoline in the engine of my '83 300D? I know this will generate a furious debate . . . LOL. So, let's discuss proper, vs. other oils used in gas cars.

Also, what about using 15W40 oil in gas engines?

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1983 300D, the "Avocado"
1976 240D, 4-spd the "Pumpkin", SOLD to Pierre
1984 190D, 2.2L, 5-spd, my intro to MBZ diesels, crashed into in 2002

This should NOT be a debate. Most readers of this forum will agree that an oil specifically blended for diesels is best for these engines.

Oils such as Shell Rotella T, Mobil Delvac and Chevron Delo have added amounts of ZDDP and detergent additives. The ZDDP is a high pressure additive necessary for your sliding valve mechanism as opposed to newer cars with roller tappets. The detergents are necessary for soot dispersal in a diesel engine.

Choose one of them or an equivalent and leave the common Premium Motor Oils for the late model gas engines.

Hope this helps

__________________
2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

"15W40" describes to the oil's viscosity and says nothing whatsoever about the type(s) of engines that it is rated for. A particular oil is either rated for a particular type engine or it's not.

I ran M1 15w40 TDT in both my 84 300D and my wife's 2001 VW Passat V6 4Motion. The Passat loved it.

__________________
Onus probandi incumbit ei qui dicit, non ei qui negat

I recondition w123/w126/w124/w140/r107/r129/ steering boxes!


1984 300D "Elsa" odo reset 6/2011 147k
1983 300TD "Mitzi" ~268k OM603 powered
1995 E300 "Adelheid" 262k [Sold]

Ran Delvac 15w40 in my E320 Cabrio....

Most oils that come in 15W40 are the diesel oils. I'm not sure what the latest designation is, but I think it is C-J4 or something like that.

All oils have a C rating, but it's not good enough unless it is an advanced rating like CJ or CK might be out now. A little googling should come up with the answer. If you get one of the oils I listed in my earlier post it will meet the recent spec.

__________________
2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

Every good diesel oil I've seen also carries a good gas rating.

I used 15w40 in my 92 Dodge 360 to help bring up the oil pressure

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

ABSOLUTELY! This is GREAT oil for earlier gas engines with already broken in flat tappet cams. It has the ZDDP additive in enough quantity to keep it healthy. Additionally the added detergents for soot dispersal help keep a gas engine squeaky clean. In fact for an old engine such as the B Mopar you talk about, I consider it mandatory.

Do not use such a heavy weight in later cars with roller cam followers. Most modern cars use something on the order of 5W20 and work best on it.

__________________
2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

I'd be using it today if the truck hadn't gotten stolen and scrapped

The Delo 15-40 seems like molasses compared to the 5-20 Mobile i use in the Mazda.

__________________
1984 300SD Orient Red/ Palomino
1989 560SEC
2016 Mazda 6 6 speed manual
1995 Ford F-150 reg cab 4.9 5speed manual

Actually, as a trucker, driving only diesel engines, I've been told, and haven't seen anything to dispute it, that the only oil that is set up as 15W40 is oil designated for diesel engines. I have yet to see any 15W40 out there that doesn't have a rating for diesels.

There is also a Walmart brand of diesel engine oil 15W40 that turns out to be Pennzoil, for about $10/gal. I have used that in my 300D and also my Cummins N-14 engine, and it has done a good job. I do prefer the thickness of Delo 400, though, but am limited by $$ right now.

I know quite a few truckers who do use the 15W40 in their gas engines. I am thinking of putting it into the SUV, but will stick to the Tectiion from Castrol. Right now am using Castrol 20W50. Castrol is known for keeping the engines clean by suspending all gunk for the filters to pick up.

Any other voices out there?

__________________
1983 300D, the "Avocado"
1976 240D, 4-spd the "Pumpkin", SOLD to Pierre
1984 190D, 2.2L, 5-spd, my intro to MBZ diesels, crashed into in 2002

None of which has anything to do with whether a particular 15W40 (or any other weight) oil is rated for gasoline engines.

Rather make decisions on the basis of rumor and hearsay than rely on the API rating?

The use of anything other than Chevron Delo 400 15W-40 in your diesel will cause:

A: The pistons to overheat, expand beyond the cylinder walls and create a temporal void in the time stream due to the creation of black matter.

B: Excessive cylinder wall scoring leading to an extreme smoke loss which will single handily cause immediate and irreparable damage to the ozone layer wiping out all living intelligent beings (only members of Congress will be left to re-populate the planet. Do you really want THAT on your conscience?).

C: An immediately lock-up of your engine which since your engine just happens to be in exact harmony with the Earth's rotation, will cause the planet to stop and reverse on its axis. The side effect of this is the smog will blow AWAY from California and millions of the local population will die from excessive exposure to the sun.

Sheesh! You might as well ask if it's okay to run WVO in your car!

Yes, but it sounds like you are using the best oil for each application. Most of the modern gas engines, most any engine originally introduced with roller cam followers are best served with a Premium thin weight oil. Not so for the old flat tappet engines or our diesels.

__________________
2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

That's also been my observation. Any oil that I've seen in 15W40 has been a diesel type oil. I expect that the store brands are just fine in almost all cases. After all, does Wal-Mart own a refinery? I don't think so. It is simply repackaged product from someone who does own one.

__________________
2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution