Ford 2002 F650 Owner's Manual page 186

Maintenance and Specifications
F˚
C˚
EXPECTED TEMPERATURE RANGE
Using the chart, determine which SAE viscosity grade best suits the
temperature range in which you expect to operate your vehicle. The use
of the correct oil viscosity grade for diesel engines is important for
satisfactory engine operation.
A symbol has been developed by the American Petroleum Institute (API)
to help you select the proper engine oil. The symbol will be included on
the oil container you purchase.
The top section of the symbol shows
the API service category
designation. This should be CH-4/SJ.
The center section of the API
symbol shows the SAE viscosity
grade.
The lower section of the API symbol
will state energy conserving if the
engine oil has been proven to have fuel savings capabilities.
Use a Ford engine oil filter, part number FL-1995 or equivalent. This
filter protects your engine by filtering harmful, abrasive or sludge
particles.
186
SAE VISCOSITY GRADES
Preferred
5W-30
0W-30
-20 -10 0 10 20 30 40
-30 -25 -20 -15 -10
15W-40 Preferred
*
10W-30
50 60 70 80 90 100
-5 0 5 10 15 20 25 30 35 40