For 1990-2009 cars

# Info - TOP TIER Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - U.S. Only

Subject: | TOP TIER Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - U.S. Only

Models: | 2007 and Prior GM Passenger Cars and Trucks (including Saturn) (U.S. Only)

| 2003-2007 HUMMER H2 (U.S. Only)

| 2006-2007 HUMMER H3 (U.S. Only)

| 2005-2007 Saab 9-7X (U.S. Only)

This bulletin is being revised to add additional sources to the Top Tier Fuel Retailers list. Please discard Corporate Bulletin Number 04-06-04-047F (Section 06 - Engine/Propulsion System). In Canada, refer to Corporate Bulletin Number 05-06-04-022C

A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by four automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from the use of TOP TIER Detergent Gasoline.

(1) | Intake valve: 10,000 miles with TOP TIER Detergent Gasoline
(2) | Intake valve: 10,000 miles with Legal Minimum additive

#### Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards

As of November 15, 2006, all grades of the following gasoline brands meet the TOP TIER Detergent Gasoline Standards:

• | Chevron

• | QuikTrip

• | Conoco

• | Phillips 66

• | 76

• | Shell

• | Entec Stations located in the greater Montgomery, Alabama area.

• | MFA Oil Company located throughout Missouri.

• | Kwik Trip, Inc. in Minnesota and Wisconsin andKwik Star convenience stores in Iowa.

• | The Somerset Refinery, Inc. at Somerset Oil stations in Kentucky.

• | Aloha Petroleum

• | Tri-Par Oil Company

• | Texaco

#### What is TOP TIER Detergent Gasoline?

TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by four automotive companies that exceed the detergent requirements imposed by the EPA.

#### Where Can TOP TIER Detergent Gasoline Be Purchased?

The TOP TIER program began on May 3, 2004. Some fuel marketers have already joined and have introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards.

#### Where Can I find the Latest Information on TOP TIER Fuel and Retailers?

On the web, please visit www.toptiergas.com for additional information and updated retailer lists.

#### Who developed TOP TIER Detergent Gasoline standards?

TOP TIER Detergent Gasoline standards were developed by four automotive companies: BMW, General Motors, Honda and Toyota.

#### Why was TOP TIER Detergent Gasoline developed?

TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product.

#### Why did the four automotive companies join together to develop TOP TIER?

All four corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies.

#### What are the benefits of TOP TIER Detergent Gasoline?

TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of TOP TIER Detergent Gasoline will help reduce deposit related concerns.