New EPA 2027 emissions rules also mean new diesel engine oil specs. A new generation of heavy-duty engine oils will feature lower viscosity, improved thermal resistance, and possibly longer oil drain ...

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 ...

“This equipment manufacturer recommends low viscosity engine oil SAE 5W-40 for temperatures ranging from -22° F to 120° F and SAE 15W-40 from +15° F to 122° F,” says Mark Betner, heavy ...