Use of the recommended fuel is an important part of the proper maintenance of this vehicle. When driving in the U.S. and Canada, to help keep the engine clean and maintain optimum vehicle performance, we recommend using TOP TIER Detergent Gasolines.
See www.toptiergas.com for a list of TOP TIER Detergent Gasolines.

Use regular unleaded gasoline meeting ASTM specification D4814 with a posted octane rating of 87 or higher. Do not use gasoline with an octane rating below 87, as it may cause engine damage and will lower fuel economy.
Use of Seasonal Fuels
Use summer and winter fuels in the appropriate season. The fuels industry automatically modifies the fuel for the appropriate season.
If fuel is left in the vehicle tank for long periods of time, driving or starting could be affected. Drive the vehicle until the fuel is at one-half tank or less, then refuel with the current seasonal fuel.
Prohibited Fuels
Gasolines containing oxygenates such as ethers and ethanol, as well as reformulated gasolines, are available in some cities. If these gasolines comply with the previously described specification, then they are acceptable to use.
However, E85 (85% ethanol) and other fuels containing more than 15% ethanol must be used only in FlexFuel vehicles.
Caution
Do not use fuel containing methanol. It can corrode metal parts in the fuel system and also damage plastic and rubber parts.
That damage would not be covered under the vehicle warranty.
Some gasolines, mainly high octane racing gasolines, can contain an octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl (MMT). Do not use gasolines and/or fuel additives with MMT as they can reduce spark plug life and affect emission control system performance. The malfunction indicator lamp may turn on. If this occurs, see your dealer for service.
Driver Assistance Systems
California Fuel RequirementsFront Wiper Blade Replacement
Windshield wiper blades should be inspected for wear or cracking. See Maintenance
Schedule on page 11-3.
Replacement blades come in different types and are removed in different ways.
For proper windshield wiper blade length and type, see Maintenance Replacement Parts
on page 11-13.
Caution
...
If the Vehicle Is Stuck
Slowly and cautiously spin the wheels to free the vehicle when stuck in sand,
mud, ice, or snow.
If stuck too severely for the traction system to free the vehicle, turn the traction
system off and use the rocking method. See Traction Control/Electronic Stability
Control on page 9-27.
Warning ...
Connections
The required specific Onstar subscription plan includes the services that follow
to help customers stay connected.
For coverage maps, see www.onstar.com (U.S.) or www.onstar.ca (Canada).
WiFi Connectivity (If Equipped)
The vehicle has a WiFi hotspot that provides a high-speed, wireless Internet ...