INFORMATION ON ENGINE OIL REQUIREMENTS (SYCLONE ONLY)

SUBJECT: ENGINE OIL REQUIREMENTS

MODELS: 1991 GMC T PICKUP (SYCLONE)

The 4.3L turbocharged engine used in the 1991 GMC Syclone is manufactured with SAE 5W-30 engine oil for break-in purposes. However, starting with the first oil change at 2,500 miles, and at all future oil changes, SAE 10W-30 "synthetic" engine oil is required. Mobil 1 or equivalent "synthetic" oil is recommended.

See Syclone Maintenance Schedule Supplement for recommended oil change intervals.

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.