File in Section:
Bulletin No.:

Service Bulletin

Date:

06 - Engine
05-06-04-022K
September, 2014

INFORMATION
Subject:

TOP TIER Detergent Gasoline Information and Available Brands

Models:

2015 and Prior GM 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 add 2015 Model Year vehicles, include the United States,
Canada and Puerto Rico, add an Attention statement, update the graphics, the information
and include a list of TOP TIER Gasoline Retailers. Please discard Corporate Bulletin
Number #05-06-04-022J.

TOP TIER Detergent Gasoline —
General Motors Recommendation

3980710

3980709

Copyright 2014 General Motors LLC. All Rights Reserved.

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.

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September, 2014

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).

Bulletin No.: 05-06-04-022K

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.

3979169

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.

3979074

Engine intake valve using Non-TOP TIER Detergent
gasoline having the minimum detergent treat rate
with more than 1,000 mg of deposits.

Bulletin No.: 05-06-04-022K

September, 2014

Page 3

3979447

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.

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