Lubricant Gobbledegook

[smutts]

In the good old days of engine oil, one looked for the API grades on the can, these had two groups of two letters, first was "S" for spark ignition or "C" for compression ignition, followed by an alphabetical letter, "A" was just dug out of the ground crap which no car since 1930 should use,  conveniantly Morrisons sell it! So all you people with Model T's should be happy! Everyone else avoid it like the plague.
It used to be the further down the alphabet it was the better. But the modern SM lubes for petrol engines supposedly have very reduced levels of the useful stuff as they poison the catalysts of these most modern cars. The reduced levels of these additives can damage older cars, (or is this some marketing ploy?).

Are there similar things happening with diesels now that many new cars have particulate filter weirdness going on? Peugeot 307 Arrrrgh! .) Or is the best oil still the farthest down the alphabet for diesel oils.?

[rallydiesel]

Yes, there is lots of this going on. If you want to read pages upon pages of oil speak, go to tdiclub. A lot of this oils discussion is of much interest to pd-owners like myself. I, and others, have tried using ZDDP additives (the stuff you mentioned that can damage catalysts and has been reduced in today's oils). It's been shown to decrease the degree of camshaft wear that has plagued many pd's.

Lots of diesel people have been having great used oil analysis results with the new API CJ-4 oils. Particularly, Mobil 1 Turbo Diesel Truck oil and Shell Rotella 5w40 synthetic.

[theman53]

I have heard that S stood for service and C stood for Commercial...That I dont' know for sure but it would make sence since most commercial vehicles around here are diesels. I have also heard that the C rated stuff traps small particles better than S rated stuff. I really am not an expert on this, but either way Spark or Service would make sence to me.

[Rabbit on Roids]

when you are thinking small particulates, think soot.

[jtanguay]

some of the newer oils are good and have less ash for less pollution.  i think its API-CL now?  my personal choice was to stick with an excellent oil (amsoil) and run a good bypass filter for extended drains.  doesn't make much sense to change the oil when the real problem is soot contamination.

[arb]

8 years or so ago I spoke with a petroleum (chemical ?) engineer at Mobil in their synthetic division about why Mobil-1 did not have the CD-4 rating my PowerStroke required... he said there is an intentional shift in the oil industry to split the diesel and gasoline engine lubes apart. He said Mobil-1 did not have the soot suspension qualities the PowerStroke's electric over hydraulic (engine oil accumulator) injectors require so they don't jam up.  He recommended their commercial synthetic oil, Delvac-1 (not to be confused with their mineral Delvac-1300) for my diesel needs. As a commercial lube, you will not find it at China-mart or Target, but its about the same price as Mobil-1.


http://www.vesco-oil.com/bins/site/templates/splash.asp has it and NAPA can get it.

[smutts]

This all gets me to a point of brain fade, some of the expensive synthetic PD oils only have API CF, whereas the cheap and cheerfull mineral stuff at my local farm suppliers is CH-4. So? higher API grades better at wading through sludge and soot, PD stuff for less soot but insane cam & bearing loadings and near nuclear heat? PD looks good for air cooled Laverda Jota's, Ducati's & Nortons then?