A reader asks: Do you have an SAE 50 heavy duty Diesel Engine Oil for trucks that meets the API CF-2 specification?

AMSOIL Synthetic 20W-50 Premium Protection Motor OilOur answer: We do not have a “straight” SAE 50 diesel engine oil. But we do have a heavy-duty 20W-50 that would be ideal for any application requiring SAE 50. AMSOIL SAE 20W-50 Premium Protection Synthetic Motor Oil covers the API CF-2 specification along with a multitude of gasoline and diesel engine specifications. This is a heavy-duty engine oil that is suitable for older diesel truck applications.

Although it is labelled as a 20W-50, this product is very shear stable and can easily be used for applications suggesting SAE-50. “Straight-weight” oils have been supplanted by multi-grade engine oils.

Straight grade oils were once specified because early renditions of multi-grade oils were prone to shearing. They would thin-out and break down under stress, heat and long service. This is why some older heavy-duty applications suggested straight grade oils.

High-quality, modern synthetic engine oils (such as AMSOIL SAE 20W-50 Premium Protection Synthetic Motor Oil) do not use “viscosity index improvers”. Viscosity index improvers are motor oil ingredients that expand with heat to prevent the thinning of some lower quality multi-grade motor oils. Viscosity index improvers are still used by some lesser oils. AMSOIL 20W-50 has world-class resistance to shearing, boil-off and consumption, so it will stand up as well as any straight grade SAE 50 motor oil.

AMSOIL SAE 20W-50 Premium Protection Synthetic Motor Oil pours down to -36°C, providing remarkable cold weather oil flow for a 50-weight oil.

Long Service Life

AMSOIL SAE 20W-50 Premium Protection Synthetic Motor Oil is formulated for long service life of up 15,000 miles (24,000 KM) for severe service. Up to 25,000 miles (40,000km) for general use.

Covers Many Diesel And Gasoline Engine Industry Specifications

  • API CI-4 +, CH-4, CF, CF-2
  • ISO-L-EMA
  • Caterpillar ECF-1
  • JASO MA (Motorcycle)
  • MAN 271/3275
  • MTU Type 2
  • Cummins 20071, 20072, 20076, 20077
  • Volvo VDS-2, VDS
  • Mack EO-M+, EO-M
  • ACEA A3/B3, E3, E5
  • MB 228.1, 228.3, 229.1
  • Detroit Diesel 93K214

We can sell AMSOIL SAE 20W-50 Premium Protection Synthetic Motor Oil at wholesale prices in Canada and the United States. Contact us for prices using the form on this page.