Cold weather and the OM615 injector pump

[Phil_F_NM]

Today, the high here in Edgewood, NM is 21 degrees. It has gotten into the negatives recently.

The last few days I've started up my 1972 220D easier since changing the oil to 5w40 Mobil 1 Turbodiesel Truck. It will turn over much easier than back when it had the 15w40 dinosaur oil in it.
Anyway, starting in the cold weather is still difficult due to fuel delivery, I'm sure. Since I'm about to drive 2000 miles east starting on Monday, I want all the advantages I can get in starting the car and delivering fuel.

The OM615 and early 616 engines with the pneumatically governed IP don't draw warm oil off the engine so they take a while to really smooth out, or at least mine does. Maybe 8 minutes. Since the IP has its own oil sump, it doesn't heat up like the later pumps.

Right now I've got 30wt monograde dinosaur oil in the IP. Is it reasonable to think that I may get a bit better starting and performance out of either a monograde 30wt synthetic or a lighter mono dinosaur oil? Granted, the IP oil does thin out with diesel fuel and I'm thinking that the very high viscosity of the 30wt dino oil is allowing more diesel past the seals until the IP warms up.

At 20 degrees F, 30wt dino flows like very cold molasses and I can't think it's lubricating much as I think it's restricting movement of the cam and valves in the IP.

Am I on the right track here?

If I change it for the cold weather to either a lighter dinosaur or a synthetic, I will obsessively monitor the temperature. i already change it out way too often (according to a few friends) but I figure a few oz of oil is cheap enough that I can change the IP oil every month then just pour it back into the fuel tank and burn it.

Any opinions?

Phil Forrest