Frequent oil ... chart for the 6.7 Power Stroke engine in the photo below: For normal usage when the outside temperatures do not fall below 0°F, Ford recommends Motorcraft 10W-30 Super Duty ...

Diesel engine oil typically possesses a higher level of viscosity, which means it pumps at a much lower temperature and takes more heat to start flowing cleanly.

In the past, there have been similar shifts in preferred engine oil viscosity grades. An example is the transition in heavy duty diesel engine oils in the 1980s from monograde viscosity SAE 30 and ...