See also:

Gasoline Specifications (U.S. and Canada Only)
At a minimum, gasoline should meet ASTM specification D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in Canada. Some gasolines contain an octane-enhancing additive called methylcyclopentadienyl ...

Customer Assistance Offices (U.S. and Canada)
GMC encourages customers to call the toll-free number for assistance. However, if a customer wishes to write or e-mail GMC, the letter should be addressed to: United States GMC Customer Assistance ...

Tire Rotation
Tires should be rotated every 12 000 km (7,500 mi). See Maintenance Schedule on page 11‑3. Tires are rotated to achieve a uniform wear for all tires. The first rotation is the most important. ...