You can absolutely use the 5W40 in all of your rigs. The Rotella 5W40 is an excellent oil.
All of these arguments about 40 weight being too thick or not cooling the bearings as well don't hold ANY water. An oil pump is a positive displacement pump, and will pump the exact same amount of oil (unless you're in bypass) with just a slightly higher pressure. Thus, bearings operate with the same flow of oil. A 40 weight is only slightly thicker than a 30 weight at full operating temp.
And about the engine rebuilder on this site that keeps claiming thick oils are killing engines because the oil can't get into the "smaller" clearances of today's motors. Many things wrong with this claim:
1. Bearing clearances are not smaller.
2. Motors around the world (including the OP's Toyota V6) are using much thicker oils than they are here, and they last forever just the same. For severe service, thicker is the way to go.
3. If a 40 weight "cannot get into the crevaces" of the motor as well as thinner oils, such as 30 or 20 weights, why don't all car engines fail when they are started cold and the oil is WAY thicker than any 30, 40, 50, 60, or 70 weight is at operating temperature???
4. The owner's manuals of vehicles outside of North America normally list a wide range of viscosities that are acceptable to use, depending on ambient temps and type of vehicle usage. They often span everything from a 20 weight to a 50 weight. Why can non-North American motors use many different oil weights, but only use one here?
Use the Rotella 5W40 if it makes your life simpler and rest easy at night. Your truck will last a long time either way.
