Fuel System - Recommended Fuels
90buick13Bulletin 91-6E-3
Date Oct. '90
Ref. No. 91-030-6E
Corp. Ref. No. 006504R
SUBJECT: RECOMMENDED FUELS FOR NON-TURBO PORT FUEL INJECTED ENGINES
MODELS AFFECTED: ALL NON-TURBO FUEL INJECTED EQUIPPED VEHICLES
General Motors recommends that owners familiarize themselves with the information in their vehicle owner's manual pertaining to recommended fuels.
Some vehicle owners currently using unleaded fuel may experience a condition such as cold start stall and/or poor cold engine performance.
It is imperative that technicians ensure the vehicle's basic engine, controls and systems are performing properly. If all engine controls and systems are performing properly, it is recommended that the vehicle owner change to a different brand of regular grade 87 octane unleaded fuel. It may require several tank fulls of a different brand fuel before the condition improves.
Use of fuels with an octane rating higher than 87, unless specified in the vehicle owner's manual, is not required. Use of premium grade unleaded fuel, 91 octane or higher, will not enhance the vehicles cold start quality and/or cold engine performance.