Zoidberg79
New member
What do the numbers mean on the oil anyway???![]()
The number on the oil are the viscosity (how runny the oil is).
The reason for the two numbers is one is a Winter viscosity (or "weight") and the other is a summer or warm viscosity.
The first number will have a "W" next to it to represent the Winter weight.
So for a 10w-40 this has a winter weight of 10 and a summer weight of 40.
Here in OZ, the older vehicles (pre 1990) use a thick oil rated at 20w-50. This is a good viscosity for older high mile engines.
All modern vehicles now use a 10w-30, a thinner oil. Generally the more modern engines use a thinner oil.
For diesel engines most common oil sold here is either 10w-40 or 15w-40.
This is fine for our climate as heat is our biggest problem.
Ih the Nothern parts of the USA I would probably use a thinner oil like a 5w-30 or as recommended by Kubota, a 10w-30.
If numbers are within +/- 5 of what you are looking for then you don't need to worry about it too much.
Regardless of the oil type, nothing is better than oil at the correct fill level.
Just my 2 cents.