Even more importantly, diesel oil is generally more viscous, as the engines need more protection ... it coats the engine's moving internal parts with a film, preventing the parts from touching ...

Demands on heavy-duty diesel engine oils have changed alongside ... oil to thicken up significantly.” Engine oil needs to form a protective film, which prevents metal to metal contact.

Petro-Canada’s new Duron UHP 10W-30 provides improved performance and protection for heavy-duty fleets, the company said.