TDI (Turbocharged Direct Injection) is
Volkswagen Group
Volkswagen AG (), known internationally as the Volkswagen Group, is a German multinational automotive manufacturer headquartered in Wolfsburg, Lower Saxony, Germany. The company designs, manufactures and distributes passenger and commercial ...
's term for its current
common rail
Common rail direct fuel injection is a direct fuel injection system built around a high-pressure (over ) fuel rail feeding solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors (or pump nozzles). High-pressure injection ...
direct injection turbodiesel
The term turbo-diesel, also written as turbodiesel and turbo diesel, refers to any diesel engine equipped with a turbocharger. As with other engine types, turbocharging a diesel engine can significantly increase its efficiency and power output, ...
engine range that have an
intercooler
An intercooler is a heat exchanger used to cool a gas after compression. Often found in turbocharged engines, intercoolers are also used in air compressors, air conditioners, refrigeration and gas turbines.
Internal combustion engines
Mo ...
in addition to the turbo compressor.
TDI engines are used in motor vehicles sold by the Audi, Volkswagen, SEAT and Skoda marques, as well as boat engines sold by in
Volkswagen Marine
Volkswagen AG (), known internationally as the Volkswagen Group, is a German multinational automotive manufacturer headquartered in Wolfsburg, Lower Saxony, Germany. The company designs, manufactures and distributes passenger and commercial ...
and industrial engines sold by
Volkswagen Industrial Motor
Volkswagen (),English: , . abbreviated as VW (), is a German motor vehicle manufacturer headquartered in Wolfsburg, Lower Saxony, Germany. Founded in 1937 by the German Labour Front under the Nazi Party and revived into a global brand post-W ...
.
The first TDI engine, a straight-five engine, was produced for the 1989 Audi 100 TDI sedan. In 1999, common rail fuel injection was introduced, in the V8 engine used by the Audi A8 3.3 TDI Quattro. From 2006 until 2014, Audi successfully competed in the LMP1 category of motor racing using TDI engine-powered racing cars.
TDI engines installed in 2009 to 2015 model year Volkswagen Group cars sold through 18 September 2015 had an emissions
defeat device
A defeat device is any motor vehicle hardware, software, or design that interferes with or disables emissions controls under real-world driving conditions, even if the vehicle passes formal emissions testing.United States Code of Federal Regulat ...
,
which activated emissions controls only during emissions testing. The emissions controls were suppressed otherwise, allowing the TDI engines to exceed legal limits on emissions.
Volkswagen has admitted to using the illegal device in its TDI diesel cars.
Overview
TDI is the combination of two existing diesel engine technologies:
*
Direct injection— where a fuel injector sprays the diesel fuel directly into the main
combustion chamber
A combustion chamber is part of an internal combustion engine in which the fuel/air mix is burned. For steam engines, the term has also been used for an extension of the firebox which is used to allow a more complete combustion process.
Interna ...
s. This causes a more complete combustion process than using a pre-combustion chamber (known as
indirect injection
Indirect injection in an internal combustion engine is fuel injection where fuel is not directly injected into the combustion chamber.
Gasoline engines equipped with indirect injection systems, wherein a fuel injector delivers the fuel at some p ...
), which therefore increases the torque output and reduces the exhaust emissions.
[
* ]Turbocharging
In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...
— where an exhaust-driven turbine compresses the intake air, in order to obtain higher power and torque outputs from a small displacement
Displacement may refer to:
Physical sciences
Mathematics and Physics
* Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path ...
engine.[
Most TDI engines also use an ]intercooler
An intercooler is a heat exchanger used to cool a gas after compression. Often found in turbocharged engines, intercoolers are also used in air compressors, air conditioners, refrigeration and gas turbines.
Internal combustion engines
Mo ...
to lower the temperature (and therefore increase the density) of the compressed air before it enters the cylinder.[
Similar technology has been used by other automotive companies, but the "TDI" marketing term is only used by Volkswagen Group and ]Land Rover
Land Rover is a British brand of predominantly four-wheel drive, off-road capable vehicles, owned by multinational car manufacturer Jaguar Land Rover (JLR), since 2008 a subsidiary of India's Tata Motors. JLR currently builds Land Rovers ...
. Volkswagen Group uses the term SDI (which stands for "Suction Diesel Injection") for its naturally aspirated (i.e. non-turbocharged) direct-injection diesel engines.
History
Prior to Volkswagen Group's first TDI engine, the first turbocharged diesel engine used in a passenger car was an indirect injection
Indirect injection in an internal combustion engine is fuel injection where fuel is not directly injected into the combustion chamber.
Gasoline engines equipped with indirect injection systems, wherein a fuel injector delivers the fuel at some p ...
five-cylinder engine fitted to the 1978 Mercedes-Benz 300SD (W116) ''300 SD'' sedan. The first turbodiesel engine with direct injection was the 1986 Fiat Croma 2.0 TD i.d. liftback sedan.
Three years after the Fiat Croma, Volkswagen Group's first TDI engine was introduced in the 1989 Audi 100
The Audi 100 and Audi 200 (and sometimes called Audi 5000 in North America) are primarily mid-size/executive cars manufactured and marketed by the Audi division of the Volkswagen Group. The car was made from 1968 to 1997 across four generations (C ...
TDI sedan. The Audi 100 was powered by the Volkswagen 2.5 R5 TDI straight-five engine which used an electronic distributor injection pump
An Injection Pump is the device that pumps fuel into the cylinders of a diesel engine. Traditionally, the injection pump was driven indirectly from the crankshaft by gears, chains or a toothed belt (often the timing belt) that also drives the ca ...
(called "VerteilerPumpe" by Volkswagen) and two-stage direct injection. The initial version of this engine generated at 3,250 rpm and at 2,500 rpm.
TDI engines using common rail
Common rail direct fuel injection is a direct fuel injection system built around a high-pressure (over ) fuel rail feeding solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors (or pump nozzles). High-pressure injection ...
fuel injection (using piezoelectric
Piezoelectricity (, ) is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in response to applied Stress (mechanics), mechanical s ...
fuel injectors) were introduced with the Volkswagen Group 32v TDI V8 engine used in the 1999 Audi A8
The Audi A8 is a full-size luxury sedan manufactured and marketed by the German automaker Audi since 1994. Succeeding the Audi V8, and now in its fourth generation, the A8 has been offered with both front- or permanent all-wheel drive—and in s ...
3.3 TDI Quattro, two years after the 1997 Alfa Romeo 156
The Alfa Romeo 156 (Type 932) is a compact executive car produced by the Italian automobile manufacturer Alfa Romeo. It was introduced at the 1997 Frankfurt Motor Show as the replacement for the Alfa Romeo 155. The 156 received a positive recep ...
''2.4-L JTD'' became the first passenger car to use common rail injection.
In 1999, the Volkswagen 1.2-litre TDI won the International Engine of the Year categories for "1.0 to 1.4 litres" and "Best Fuel Economy".
In 2000, a fuel system using unit injectors (called "Pumpe Düse" by Volkswagen) began to replace the distributor injection pump systems (except for the V8 engine, which used common rail design).[ In 2003, upgraded fuel injectors using a piezoelectric design began to replace the previous solenoid-operated unit injectors.
Since 2009, most of the Volkswagen Group TDI engines have switched from unit injectors to common rail injection.
]
Emissions testing falsification
On 18 September 2015 the US EPA
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...
and California Air Resources Board
The California Air Resources Board (CARB or ARB) is the "clean air agency" of the government of California. Established in 1967 when then-governor Ronald Reagan signed the Mulford-Carrell Act, combining the Bureau of Air Sanitation and the Motor ...
served notice to VW that approximately 480,000 VW and Audi automobiles equipped with 2.0 TDI engines sold in the US between 2009 and 2015 had an emissions compliance defeat device
A defeat device is any motor vehicle hardware, software, or design that interferes with or disables emissions controls under real-world driving conditions, even if the vehicle passes formal emissions testing.United States Code of Federal Regulat ...
installed. The defeat device, in the form of specially crafted engine management unit firmware
In computing, firmware is a specific class of computer software that provides the low-level control for a device's specific hardware. Firmware, such as the BIOS of a personal computer, may contain basic functions of a device, and may provide h ...
, detects emissions testing conditions, and in such conditions will cause the vehicle to comply with emissions regulations by properly activating all emissions controls. However, under normal driving conditions, the emissions controls are suppressed, allowing the engine to produce more torque and get better fuel economy, at the expense of emitting up to 40 times more nitrogen oxide Nitrogen oxide may refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds:
Charge-neutral
*Nitric oxide (NO), nitrogen(II) oxide, or nitrogen monoxide
*Nitrogen dioxide (), nitrogen(IV) oxide
* Nitrogen trioxide (), or n ...
s than allowed by law. Such NOx emission levels are not in compliance with US regulations. VW has since admitted to these allegations, and said that the illegal software was in use in its diesel cars worldwide, affecting some 11 million vehicles.
Motor racing
The first TDI engine used by Volkswagen Group for motor racing was in the Audi R10 TDI
The Audi R10 TDI, usually abbreviated to R10, is a diesel-powered racing car from the German car manufacturer Audi. The car dominated Le Mans, winning each year from its 2006 introduction until it was replaced by the R15 in 2009. It was designe ...
, which competed in the Le Mans Prototype
A Le Mans Prototype (LMP) is the type of sports prototype race car used in the 24 Hours of Le Mans, FIA World Endurance Championship, IMSA SportsCar Championship, European Le Mans Series and Asian Le Mans Series. Le Mans Prototypes were create ...
(LMP) class of sports car racing. The Audi R10 recorded a victory on its debut at the 2006 12 Hours of Sebring race and then at the 2006 24 Hours of Le Mans
The 24 Hours of Le Mans (french: link=no, 24 Heures du Mans) is an endurance-focused Sports car racing, sports car race held annually near the town of Le Mans, France. It is the world's oldest active Endurance racing (motorsport), endurance r ...
race, with both results being the first time that a diesel-powered car had won each race. In the nine years from 2006 to 2014, the R10 and its successors ( R15 and R18) won the 24 Hours of Le Mans eight times (the 2009 race was won by another diesel-powered car, the Peugeot 908 HDi FAP
The Peugeot 908 HDi FAP is a sports prototype racing car built by the French automobile manufacturer Peugeot to compete in the 24 Hours of Le Mans endurance race, starting in 2007 and eventually winning in 2009. This effort, in development sin ...
).
In the World Touring Car Championship
The FIA World Touring Car Championship was an international touring car championship promoted by Eurosport Events and sanctioned by the Fédération Internationale de l'Automobile (FIA). It has had several different incarnations, including a sin ...
(WTCC) racing series, the SEAT León TDI won the 2008 championship and the 2009 championship for drivers and manufacturers. In 2008, the SEAT Leon TDI also competed in the British Touring Car Championship
The Kwik Fit British Touring Car Championship is a touring car racing series held each year in the United Kingdom, currently organised and administered by TOCA
TOCA, formally trading as BARC (TOCA) Ltd, is an organiser of motorsport events in ...
(BTCC) and became the first diesel car to win a round of the championship when it won the round at Donington Park
Donington Park is a motorsport circuit located near Castle Donington in Leicestershire, England. The circuit business is now owned by Jonathan Palmer's MotorSport Vision organisation, and the surrounding Donington Park Estate, still owned b ...
.
See also
*Common rail
Common rail direct fuel injection is a direct fuel injection system built around a high-pressure (over ) fuel rail feeding solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors (or pump nozzles). High-pressure injection ...
*Diesel automobile racing Diesel automobile racing can refer to any use of diesel as a fuel for racing cars. The diesel-fueled vehicle may be used in direct competition with other vehicles, in a separate Diesel class in the same racing event, or in a diesel-only event.
Die ...
*Diesel engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...
* Direct injection
*List of Volkswagen Group diesel engines
List of Volkswagen Group diesel engines. The compression-ignition diesel engines listed below are currently used by various marques of automobiles and commercial vehicles of the German automotive concern, Volkswagen Group,ETKA official factory ...
*List of discontinued Volkswagen Group diesel engines
List of discontinued Volkswagen Group diesel engines. The compression-ignition diesel engines listed below were formerly used by various marques of automobiles and commercial vehicles of the German automotive concern, Volkswagen Group,ETKA offic ...
*SDI (engine)
The SDI engine is a design of naturally aspirated (NA) direct injection diesel engine developed and produced by Volkswagen Group for use in cars and vans, along with marine engine (Volkswagen Marine) and Volkswagen Industrial Motor applications. ...
*Turbo-diesel
The term turbo-diesel, also written as turbodiesel and turbo diesel, refers to any diesel engine equipped with a turbocharger. As with other engine types, turbocharging a diesel engine can significantly increase its efficiency and power output, ...
References
{{Volkswagen Group brands , state=expanded
Volkswagen Group engines