05-06-04-022L

File in Section:
Service Bulletin
Bulletin No.:
Date:
06 - Engine
05-06-04-022L
November, 2014
INFORMATION
Subject:
TOP TIER Detergent Gasoline Information and Available Brands
Models:
2015 and Prior GM Passenger Cars and Trucks
United States, Canada and Puerto Rico
Attention: Gasolines that have met the TOP TIER Detergent Standards will appear on the list of
TOP TIER Gasoline brands at this website under the Retailers tab: www.toptiergas.com
This Bulletin has been revised to update the list of TOP TIER Gasoline Retailers.
Please discard Corporate Bulletin Number 05-06-04-022K.
TOP TIER Detergent Gasoline — General Motors Recommendation
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A class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of various fuel marketers in the
United States, Canada and Puerto Rico. This gasoline meets the detergent standards developed by seven
automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing
the “Lowest Additive Concentration” (LAC). LAC is also known as the minimum detergent treat rate, recommended
by the Environmental Protection Agency (EPA) in the United States and in Canada, the Canadian General
Standards Board (CGSB). Those vehicles that have experienced engine deposit related concerns may especially
benefit from using TOP TIER Detergent Gasoline.
GM strongly recommends the use of TOP TIER Detergent Gasoline. TOP TIER Detergent Gasoline is guaranteed
not to contain harmful organometallic additives, which are sometimes used to raise a fuel’s octane rating and could
harm the vehicle’s emission system.
The EPA and CGSB require only a minimum amount of detergent in gasoline. This minimum amount is not adequate
to keep the engine running at optimal conditions for the life of the vehicle. TOP TIER Detergent gasoline contains 2–
3 times more detergent than the EPA and CGSB minimum requirement, resulting in a lower amount of intake valve
deposits (IVD). These IVD’s can negatively affect fuel economy, emissions, and performance.
General Motors, BMW, Honda, Toyota, Volkswagen, Audi and Mercedes-Benz developed the TOP TIER Detergent
Gasoline Standards and support the use of TOP TIER Detergent Gasoline by recommending it in their vehicle
Owner Manuals. All seven corporations recognize the benefits to the vehicle, the environment, and the consumer.
Additionally, the companies recognize that by joining together they can better address the industry concern with low
fuel detergency levels and the intentional addition of metallic additives.
This is a voluntary program for fuel marketers and not all fuel marketers will offer TOP TIER Detergent gasoline.
When fuel marketers make public announcements regarding that their gasolines have met the TOP TIER Detergent
Standards, they will appear on the list of brands under the Retailers tab at the Home website of
www.toptiergas.com
A Cleaner Engine Has Environmental and Vehicle Performance Advantages
The following engine intake valve graphics show the difference between an engine that did not use TOP TIER
Detergent gasoline and an engine that did at 10,000 mi (16,093 km).
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Engine intake valve using Non-TOP TIER Detergent gasoline having the minimum detergent treat rate with
more than 1,000 mg of deposits.
Deposits (1) on the intake valve reduce fuel economy by creating a porous surface that collects wet fuel, thereby
affecting the air to fuel mixture in the cylinder and releases fuel late in the combustion cycle leading to increased
unburnt hydrocarbon (HC) and carbon monoxide (CO) emissions (2). Likewise fuel injectors may become restricted
with carbon deposits over time resulting in an incorrect injector spray pattern and similarly increasing HC and CO
emissions.
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Engine intake valve using TOP TIER Detergent gasoline having a high detergent treat rate with less than
50 mg deposits.
As can be seen, this intake valve is significantly cleaner resulting in optimal fuel economy and driveability
performance as well as reduced emissions.
TOP TIER Gasoline Retailers — United States, Canada and Puerto Rico
Additional gasoline retailers are added to the TOP TIER list when their gasolines meet the TOP TIER Detergent
Gasoline Standards. For the most up to date list of fuel marketers that offer TOP TIER Detergent Gasoline, refer to
this website: www.toptiergas.com
The following list is the most current list of the latest gasoline brands that meet the TOP TIER Detergent Gasoline
Standards in all octane grades, in the United States, Canada and Puerto Rico.
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