For 1990-2009 cars

# SERVICE MANUAL UPDATE SEC. 0B MAINTENANCE & LUBRICATION

#### SUBJECT: SMU - SECTION OB MAINTENANCE AND LUBRICATION (ENGINE OIL VISCOSITY CHARTS)

#### VEHICLES AFFECTED: 1991 A, C, H W/2.5L, 3.3L, 3.8L ENGINE

THIS BULLETIN HAS BEEN REVISED TO CHANGE THE FIGURE NUMBER IN FIRST SENTENCE UNDER THE "A CAR" READING.

#### A CAR:

Page 0B-4 Figure 3 only applies to the 2.5L (VIN R) engine. The chart below (Figure L39264-0B-R1) was not included in the service manual and applies only to the 3.3L (VIN N) engine.

#### C AND H CARS:

Page 0B-1 of both of these service manuals contains an 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 3.

Please mark a reference to this bulletin in your copies of the 1991 A, C and H 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.