Which Viscosity is Better for Ford 1720 30W or 15W40

[Rick]

I have been using 15/40 as it is said to degrade more slowly but I am wondering if I should use the 30W the former owner was using.

I've had some guys pulling logs out of the woods and they have been working the tractor pretty hard. They think I should change the oil even though there are only 75 hours on the oil - which I will do to be on the safe side.

The tractor is generally used for transporting materials, and also brush-cutting 40 hours a year.

I am wondering what is the best viscosity oil to use. Should I use the 30W and change it sooner than 100 hours as ford suggests?

[SamEwing]

If any of the operating is done in the winter months, stay with the 15/40.
It gets pretty darn cold there in WV.

If the primary usage is summer, 30 would be OK.

I would consider 20w50 if it were mine.

[mightybooboo]

Well for sure you cant go wrong with changing oil sooner as far as engine is concerned,if you have a feeling you should change it go with your gut feeling is what I do when unsure.

[Windy in Kansas]

The owner's manual calls for 15-40, and under certain temperature conditions 30.

I'd stick with the 15-40, but I do use the Ford product in mine.

If your fuel has high sulphur content then I would change more frequently than the recommended 100 hours or if in extremely dusty conditions.

[Beeman]

I'd stick with 15w-40 and use Rotella,Delvac or Delo.