Dexron
Encyclopedia
Dexron is the trade name
for a group of technical specifications
of automatic transmission fluid
created by General Motors
(GM). The name is a registered trademark of GM, which license
s the name and specifications to external companies which manufacture the fluid and sell it under their own brands. GM has upgraded the Dexron specifications over the years; newer fluids are generally but not always backward compatible
with previous Dexron fluids. The current fluid is Dexron-VI, introduced in 2005.
Originally the Dexron name was associated exclusively with automatic transmission fluids, but more recently GM
has released Dexron-branded gear oil
s.
as a friction modifier
. The U.S.
Endangered Species Act
banned the import of sperm whale oil, so Dexron fluid had to be reformulated.
. However, it made problems with corrosion-prone solder in GM's transmission fluid coolers and so had to be reformulated.
of Dexron-III, compared to previous fluids, improves fuel economy
by reducing parasitic loss
within the transmission.
Brand
The American Marketing Association defines a brand as a "Name, term, design, symbol, or any other feature that identifies one seller's good or service as distinct from those of other sellers."...
for a group of technical specifications
Specification (technical standard)
A specification is an explicit set of requirements to be satisfied by a material, product, or service. Should a material, product or service fail to meet one or more of the applicable specifications, it may be referred to as being out of specification;the abbreviation OOS may also be used...
of automatic transmission fluid
Automatic Transmission Fluid
Automatic transmission fluid is the fluid used in vehicles with self shifting or automatic transmissions. It is typically colored red or green to distinguish it from motor oil and other fluids in the vehicle...
created by General Motors
General Motors
General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...
(GM). The name is a registered trademark of GM, which license
License
The verb license or grant licence means to give permission. The noun license or licence refers to that permission as well as to the document recording that permission.A license may be granted by a party to another party as an element of an agreement...
s the name and specifications to external companies which manufacture the fluid and sell it under their own brands. GM has upgraded the Dexron specifications over the years; newer fluids are generally but not always backward compatible
Backward compatibility
In the context of telecommunications and computing, a device or technology is said to be backward or downward compatible if it can work with input generated by an older device...
with previous Dexron fluids. The current fluid is Dexron-VI, introduced in 2005.
Originally the Dexron name was associated exclusively with automatic transmission fluids, but more recently GM
General Motors
General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...
has released Dexron-branded gear oil
Gear oil
Gear oil is a motor oil made specifically for transmissions, transfer cases, and differentials in automobiles, trucks, and other machinery. It is of a higher viscosity to better protect the gears and usually is associated with a strong sulfur smell. The high viscosity ensures transfer of...
s.
Automatic transmission fluids
The original Dexron transmission fluid was introduced in 1968 as an improvement over the previous "Type-A, Suffix-A" fluid. Over the years, the original Dexron was supplanted by Dexron-II, Dexron-IIE, Dexron-III, and Dexron-VI, which is the current fluid. Because there are still applications for which Dexron-VI is either not suitable or not necessary, there remains a market for fluids meeting older Dexron specifications.Dexron
The original Dexron fluid, like its predecessor Type-A/Suffix-A, used sperm whale oilWhale oil
Whale oil is the oil obtained from the blubber of various species of whales, particularly the three species of right whale and the bowhead whale prior to the modern era, as well as several other species of baleen whale...
as a friction modifier
Friction modifier
Friction modifiers are added to lubricants to reduce the surface friction of the lubricated parts. Typically these are polar chemical compounds having high affinity for metal surfaces and possessing long alkyl chains....
. The U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
Endangered Species Act
Endangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...
banned the import of sperm whale oil, so Dexron fluid had to be reformulated.
Dexron-II
Dexron-II was introduced in 1972 with alternative friction modifiers such as Jojoba oilJojoba oil
Jojoba oil is the liquid wax produced in the seed of the jojoba plant, a shrub native to southern Arizona, southern California, and northwestern Mexico. The oil makes up approximately 50% of the jojoba seed by weight....
. However, it made problems with corrosion-prone solder in GM's transmission fluid coolers and so had to be reformulated.
Dexron-IID
Corrosion inhibitors were added to Dexron-II to address the solder corrosion issue. The resultant fluid, released in 1975, was called Dexron-IID. However, the corrosion inhibitor made the new fluid hygroscopic to a problematic degree, and so had to be reformulated.Dexron-IIE
Dexron-IIE was introduced in an effort to address the hygroscopicity problems with the previous IID fluid.Dexron-III
In 1993, GM released new Dexron-III fluid. It is generally backward-compatible with transmissions originally filled with earlier Dexron fluids or with Type-A/Suffix-A fluid. The lower viscosityViscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
of Dexron-III, compared to previous fluids, improves fuel economy
Fuel economy
Fuel economy may refer to:*Fuel economy in automobiles, refers to the fuel efficiency relationship between distance traveled by an automobile and the amount of fuel consumed*Fuel efficiency in general...
by reducing parasitic loss
Parasitic loss
Parasitic loss is that which a parasite consumes from its host, for whom the loss may or may not be beneficial.- Parasitic loss in internal combustion engines :...
within the transmission.