c.
Oil Viscosity
Oil viscosity (thickness) is described by SAE (Society of Automotive Engineers) Viscosity Grade. Colder
temperatures require lower viscosity oils to ensure good flow during starting, while hotter temperatures require
higher viscosity oils for satisfactory lubrication. Based upon the temperature range you expect before your next oil
change, use the oil viscosity chart and the notes below to choose the proper viscosity grade. Using other viscosity
grades, or using viscosity grades at temperatures outside the recommended ranges could result in engine
damage.
d.
Oil Change Interval
(1)
Refer to Maintenance Section of this manual for the recommended oil change interval. Use of oils exceeding
the required quality level, synthetic oils, or other oils claiming longer service intervals does not justify extending oil
change intervals beyond those recommended.
(2)
For diesel engines, the recommended oil change intervals are based on the use of diesel fuels with a
maximum sulfur content of 0.5 percent. Know your fuel sulfur content. (Ask your supplier, or have fuel analyzed).
If fuel contains more than 0.5 percent sulfur, reduce the oil change interval as follows:
NOTE
It is NOT necessary to reduce filter change intervals when oil change intervals are reduced.
Sulfur Content, Percent
Oil Change Interval
Below 0.5
Normal
0.5 to 1.0
1/2 Normal
Above 1.0
1/4 Normal
4-3
