I've noticed that the Delo 400 oil for my D*dge diesel is:
15W-40 for conventional oil
10W-40 for synthetic blend
5W-40 for full synthetic
It's the same for Rotella, I think. Does that mean that the synthetics are better lubricating at lower temps so they can go less viscous?
1948 3/4-Ton 5-Window Flatbed Chevrolet 34 Years. Now with a '61 261, 848 head, Rochester Monojet carb, SM420 4-speed, 4.10 rear, dual reservoir MC, Bendix up front, 235/85R16 tires, 12-volt w/alternator, electric wipers and a modern radio in the glove box.
