Originally Posted By: bubbatime
That Ford 300 straight six was basically designed in the 50's and 60's. It's an OLD design. A 0W20, in Texas, is a TERRIBLE choice for that engine. If you want a common shared oil, use the same Rotella 5W40 as you use in your other car.
I agree. Having owned 5 vehicles with that engine, a 20 grade oil is not a good idea. The engine was not made to run that oil. A 0W30, 5W30, 0W40 or 5W40 would be much better suited. IIRC there is no mention of 20 grade oil as an option in the owners manual from my 1988 E-150 with the 4.9L engine.
That Ford 300 straight six was basically designed in the 50's and 60's. It's an OLD design. A 0W20, in Texas, is a TERRIBLE choice for that engine. If you want a common shared oil, use the same Rotella 5W40 as you use in your other car.
I agree. Having owned 5 vehicles with that engine, a 20 grade oil is not a good idea. The engine was not made to run that oil. A 0W30, 5W30, 0W40 or 5W40 would be much better suited. IIRC there is no mention of 20 grade oil as an option in the owners manual from my 1988 E-150 with the 4.9L engine.