Best oil for 2.4D DW?

[blix99]

Hi there. I have a 1983 2.4D DW in a VW LT camper van, in the UK.
I've read a few posts; here and on other forums, about which oil to use but nothing seems conclusive.

Mineral? Semi Synthetic? Fully synthetic? What grade?
I found an LT owners manual in German that seems to suggest 15w40 mineral but this was from the late 1980s so think things might have moved on from here. It also specifies VAG 501 01 but since this forum is predominately Volvo and uses the same engine, I can't see the VAG spec oil makes much difference?

From what I've read, mineral oil deteriorates quicker and leaves more mess whereas Synthetic, either semi or fully, cleans the internals?

Any advice for the best option to keep my engine running tip top would be greatly received : )

Cheers

[v8volvo]

It is pretty conclusive, fortunately.

Fully synthetic 5W40 is what has given best results for these engines and others related to them. The engines are more or less immune to internal wear if they have good synthetic diesel rated oil in them of any reasonable grade.

Some like 5W30, but 5W40 gives better protection when hot and has no downsides. I myself pay a little extra and run 0W40, which has even wider viscosity spread and also no downsides, but that's mainly for the benefit it gives when trying to start the engine unassisted in midwinter temperatures at altitude, when it needs all the help it can get from faster cranking speeds. You probably don't get the -35C winter weather there that we have in this area so I imagine 5W40 would be a perfectly good choice. The only time 0W and 5W perform any differently is in extreme cold.

Synthetic oils like the ones we can get today weren't widespread or well proven 40+ years ago when these engines were new, hence their not being specified in original literature. But now that they are commonplace, they are indeed specified from the factory for closely related engines (like VW TDI, etc) that were released more recently and use an almost identical mechanical design. Thus, it seems assured that if a D24 were still on the market today, it too would have a synthetic (VW505.00) spec from the factory. But in any event it's what should be used, original factory specifications notwithstanding.

There are many good options so just pick your favorite brand or whatever's easily found near you at a reasonable price. Many like Mobil 1, Rotella T6, Castrol, Lubro Moly, Rowe, Fuchs, ELF, Pentosin, etc. Anything with a full synthetic formulation and 5W40 weight meeting the 505.00 spec and rated for diesel use will do well.

[blix99]

Superb. You should get this added as a sticky.
Thanks very much. I'm off to find some now : )