Most internal combustion engines rely on motor oil for one reason: lubrication. The oil gets pressurized between 10-70 psi and spends most of its life subjected to roughly 200 degrees’ worth of heat.

If you've been considering a Ram or Ford heavy-duty truck for your next purchase, you might be wondering about how the 6.7 Cummins and Ford 6.7 Powerstroke compare, and understandably so. These two ...