Rotella users: T4 or T6?

[rmel]

I've used Phillips X/C for years the anti-wear package is LW-16702 approved and
required by Lycoming. I too was initially worried about what anti-wear was used.
It's good stuff. I'd have no qualms switching back but I kinda have dialed in Lucas
Classic at least for now.

[JimmyC]

I just went through a bit of studying on oil for the Pinz. Here is my 2 cents:

First any oil you can buy today is better than what was available in 1972. In 1972 the oil changed in viscosity a lot more than modern oil. Even modern SAE 30 is something like 20w30. My Pinz manual says to use SAE 30 in the summer and SAE 10 in the winter. When it is cold SAE 30, especially the older fashion stuff, is too thick to flow well. It mostly gets dumped out the pressure relief valve and you have real poor lubrication until it gets warm. It can also make for hard starting. When it gets warm SAE 10 gets to thin when it gets up to temperature. SAE 10W30 has the same viscosity as SAE 10 at 104f and SAE 30 at 212f. When it is below 104f 10W30 is a little thinner than SAE 30. When it gets above 212f 10w30 is a little thicker than SAE30. What this all boils down to is 10W30 is probably a pretty good oil weight for a Pinz. You should be able to start when it is really cold and your oil will not be too thin when it is really hot. If you live somewhere very cold you might want 5W30, and I think you can go up to 10W40 and be ok. If you live where it never gets cold then SAE 30 is fine.

Next having at least some mineral oil in the mix is good because Pinzgauer seals were designed and tested with mineral oil. Mineral oil makes seals from back then swell. If you get them off mineral oil they might leak.

Finally additive packages. When they started putting catalytic converters on cars they had to take most of the zinc additives out to protect the catalytic converters. The zinc additives (ZDDP) were what kept the cams and tappers from scuffing. Supposedly they put some other stuff that is just as good but who knows. So ideally you want some oil with some ZDDP in it. Several companies make “old car” oil that still has ZDDP in it and most oil for diesels still have it. I doubt the Pinz has a highly stressed valve train because it was designed for junk oil, but the oil with the ZDDP will probably result in less wear.


Finally most of the benefit of synthetic oil other than better viscosity index is long life, but with a Pinz you are probably better off just changing it more often. I say this because the unventilated crankcase means all sorts of combustion products and water vapor are going into your oil. The stuff is going to get nasty long before it thickens due to oxidation. So no need for expensive synthetic unless you need it for a really cold climate.

[VinceAtReal4x4s]

I'll add to the case for synthetic in another scenario, and one I have been in a few times, and that is- long trips.

A multi-week long exploration trip is something I've done a few times in an old 4x4. Once in my 303, I did well over 3000 miles in a month when I stayed in Moab for 3 weeks. This is a perfect case for a high-end oil to me. The prolonged heat issues alone is good enough reason to use something that will handle the heat far better. This was a mix of a lot of offroading then 2000+ miles on the highway at top speed.

My fun 4x4 these days is a VW Syncro van and I'll do a 1000 mile trip across a wide variety of temperatures and terrain a couple times a year. It has a 2.2 Subaru engine in it and it only gets filled with Pennzoil Ultra Platinum oil. (never thought I'd use Pennzoil but this stuff is the new budget Amsoil alternative)