Buick 1998 Riviera Owner's Manual page 326

Short TripKity Maintenance Schedule
Lubricate chassis components (or every 6 months, whichever occurs first).
[7
Rotate tires. See "Tire Inspection and Rotation" in the Index for proper
(See footnote
#.)
rotation pattern and additional information. (See footnote
+.)
75,000 Miles (125 000 km)
0
Change engine oil and filter (or every
3
months, whichever occurs first).
0
Inspect air cleaner filter if you are driving in dusty conditions.
An Emission Control Service.
Replace filter if necessary.
An Emission Control Service. (See footnote?.)
78,000 Miles (130 000 km)
Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.
Lubricate chassis components (or every 6 months, whichever occurs first).
0
Rotate tires. See "Tire Inspection and Rotation" in the Index for proper
(See footnote
#.)
rotation pattern and additional information. (See footnote
+.)
I
DATE
I
MILEAGE
DATE
7-17