Re:  Labeling is now changing and in the Diesel world we have post and pre
2007 oil requirements. Most of the pre 2007 is disappearing. Some of the new
stuff brags about "emissions system performance". The real early heavy duty
Diesel oils can affect the catalyst and O2 sensors.  (Dennis)

Your knowledge here needs updating ...

ESP = emission systems protection

There's no "bragging" to it.

The system at risk with the older oils is the diesel particulate
filter--which is not the same thing as the catalytic converter.

The new oils are low ash so as not to leave excessive deposits in the DPF.
What deposits there are are periodically burned off by injection of fuel
into the filter.

On my Mercedes GL320 CDI there's a decal under the hood warning to never put
ANY QUANTITY of non conforming motor oil in the engine.  I carry a couple
spare quarts.

Someday I'm going to have to pay for a replacement DPF and it's going to be
expensive and I'm for sure not going to do anything to hasten its demise.

The DPF requirement is a great thing, as unfiltered diesel exhaust is quite
lethal.  I've on occasion when messing with trailer hookup noted that the
smell of DPF filtered exhaust is mostly that of steam--I call it
"laundromat."  There's zip/zero/nada traditional diesel smell nor is there
black soot all over the exhaust outlets or the rear of the car.

This has also nothing to do with "heavy" oil, as generally speaking these
days lower viscosity oils are specified, mostly to reduce friction and
increase fuel mileage since there are gov't economy requirements.  The
Mercedes 229.51 spec oil I use is Mobil 1 Formula M 5W-40 and in terms of
"heavy" only the 40 is meaningful and if one studies up on Mobil 1 you'll
find very little difference between 40 and 50, but I still use good old
15W-50 Mobil 1 in my aircooled Vanagon.

Kent Christensen
Albuquerque
'81 Vanagon, rubber floors, vinyl seats