What weight of oil do you use in a ford V10?

Answer 1

I know the manual says 5-20, but read Ford bulletins saying they use it to boost their CAFE ratings. Similar to what Honda is doing now. I have a Mercedes that uses 0-40 M1. The timing chain always rattles when first start the engine after the car is parked for a fed days. The dealer has told me its fine - they all do it. After the free maintenance ran out when the warranty expired I switched to 10-40 and now the engine runs smoother and the timing chain rattle has gone away. The manual says its ok to use it if the temperature is above 0. BTW, that's how older cars specified what oil is to be used - all based on temperature. So I'm using 10-30 semi-synthetic in my motorhome - Ford v10. I hope this helps you make your decision.