If ANY of these apply to you, then change your engine oil
at every interval shown in schedule ЉBЉ of the ЉMainte-
nance SchedulesЉ section of this manual.
If none of these apply to you, then change your engine oil
at every interval shown on schedule ЉAЉ of the ЉMainte-
nance SchedulesЉ section of this manual.
NOTE: Most vehicles are operated under the conditions
listed for Schedule ЉB.Љ
Engine Oil Selection
1. Engine Oil Quality
Use only oils conforming to API Ser-
vice CI-4. A sulfated ash limit is speci-
fied for lubrication oil used in Cum-
mins engines. Oils with a high ash
content may produce deposits on
valves that can progress to guttering
and valve burning. A maximum sulfated ash content of
1.85 mass % is recommended for all oil used in the
engine.
2. Engine Oil Viscosity (SAE Grade)
The proper SAE viscosity of engine oil for the expected
ambient temperature range should be selected, as indi-
cated in the following chart:
NOTE: The same oil change interval is to be followed
for synthetic oil as for petroleum based oil. Also, syn-
thetic oil must meet the same performance specifications
as petroleum oil.
MAINTAINING YOUR VEHICLE 385
7