SERVICE MANUAL UPDATE SEC. 0B MAINTENANCE & LUBRICATION

SUBJECT: SERVICE MANUAL UPDATE (ENGINE OIL VISCOSITY CHARTS)

MODELS AFFECTED: 1991 CUTLASS CIERA, EIGHTY-EIGHT, NINETY EIGHT

1991 CUTLASS CIERA/CRUISER SERVICE MANUAL: ------------------------------------------ Page 0B-4 Figure 3 only applies to the 2.5L (VIN R) engine. The chart below was not included in the service manual and applies only to the 3.3L (VIN N) engine.

1991 88 AND 98 SERVICE MANUALS:

Page 0B-1 of bothe of these service manuals contains and error. At the end of the left-hand column, the reference to "5W30" should be crossed out. 5W30 is an acceptable viscosity but only within a certain temperature range. The correct engine oil viscosity recommendations are shown on page 0B-4 within Figure 4 or as shown below.

Please mark a reference to this bulletin in you copies of the affected service manuals.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.