SAN DIEGO – Is it time to rethink engine oil viscosity to allow multigrades even lighter than today’s SAE 0W-20 oils? Is there a technical need for such exotic blends as SAE 5W-10 or 5W-5, or even 0W-0? That’s the puzzle facing a task force which met here last week during the SAE Powertrain, Fuels & Lubricants meeting.
The SAE J300 Engine Oil Viscosity Task Force has been considering the addition of some lower-viscosity, non-winter grades, which automakers want to help address their need for fuel economy. Non-winter grades currently stop at SAE 20, with nothing lower, and changing that will require writing new viscosities into SAE J300, the document that defines engine oil grades.