For 1990-2009 cars

# Performance Characteristics of Vehicles with Accessory Wheel/Tire Assemblies Installed as Upsized to Original Equipment

Subject: | Performance Characteristics of Vehicles with Accessory Wheel/Tire Assemblies Installed as "Upsized" to Original Equipment

Models: | 2009 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn)

| 2006-2009 HUMMER H3

This bulletin is being revised to add the 2009 model year. Please discard Corporate Bulletin Number 05-03-10-005C (Section 03 -- Suspension).

When GM Accessories wheel/tire assemblies are installed on a vehicle, customers may notice a change in the driving characteristics of the vehicle. The purpose of this document is to review the different performance characteristics of a vehicle with accessory wheel/tire assemblies installed.

#### Vehicle Performance:

Use of larger "upsized" tire/wheel assemblies, in lieu of the standard factory installed tire/wheel assemblies, can change the vehicle's overall performance characteristics. Depending on road surface and driving conditions, the driver may note changes or differences in the following:

• | Tire/road noise

• | Ride stiffness

• | Tire tread wear rate

• | Steering effort

• | Fuel economy

• | Braking performance

• | Tire traction (wet/dry/snow/ice)

Also, generally, tire chains cannot be used due to lack of clearance to the wheelhouse. Trucks equipped with accessory wheel/tire assemblies will not be compatible for use with snowplow equipment.

#### Turning Information:

Important: This section ONLY applies to the following vehicles:

• | 1999-2007 Silverado and Sierra (Classic)

• | 2000-2006 Fullsize Utilities

In a reverse turn, the tire may contact the plastic inner liner toward the rear and may also contact the sway bar. In a bounce/jounce condition, the tire may contact the top of the wheel house (the metal part inside the fender lip). These are all considered friendly surface contacts, meaning they will not damage the tire/wheel and are a characteristic of the upgrade.

### Warranty Information

All GM accessories sold and permanently installed on a GM vehicle prior to delivery will be covered under the provisions of the New Vehicle Limited Warranty.

The changes in ride handling listed above are considered normal conditions when upgrading to larger wheels/tires and are not covered by the New Vehicle Limited Warranty.

#### Wheels:

For the U.S., in the event GM Accessories are installed AFTER new vehicle delivery, or are replaced under the new vehicle warranty, they will be covered (parts and labor) for the balance of the vehicle warranty, but in no event less than 12 months/12,000 miles. This coverage is only effective for GM Accessories permanently installed by a GM dealer or a GM approved ADI (Accessory Distributor / Installer).

For Canada, in the event GM Accessories are installed AFTER new vehicle delivery, they will be covered (parts and labor) for the balance of the vehicle warranty, or up to 12 months/unlimited kilometers depending on month installed. For replacement after the new vehicle warranty expires, but within the 12 months/unlimited kilometers coverage, refer to claim type "B" guidelines.

GM Accessories sold over-the-counter, or those not requiring installation, will continue to receive the standard GM Dealer Parts Warranty of 12 months from the date of purchase (parts only).

#### Tires:

Any approved tire installed on a GM Vehicle PRIOR to delivery will be covered under the provisions of the New Vehicle Limited Warranty. Tires are covered against defects in material and workmanship. Tires are warranted for defects "without" prorated charge for tread mileage. Subsequent replacements under this warranty will continue to be covered for the remainder of the New Vehicle Limited Warranty.

Any approved tire installed on a GM Vehicle PRIOR to delivery, may continue to be warranted on a prorated basis by the tire manufacturer once the New Vehicle Limited Warranty expires.

Any approved tire installed AFTER delivery will be covered under the provisions of the tire manufacturer warranty.

U.S. dealers should refer to GM Warranty Administration Bulletin 00-03-10-003M and GM Parts Process/Policy Bulletin 1B03-001 for more information.

Canadian dealers should refer to GM Warranty Administration Bulletin 01-03-10-003E.