Saab XWD
Encyclopedia
XWD, an acronym for Cross-Wheel Drive, is an advanced all-wheel drive system designed by Haldex
in partnership with Saab
. Also known as Haldex Generation 4, it is an intelligent permanent all-wheel drive system that can pre-emptively and continuously change torque distribution before wheel slip occurs.
To achieve optimum take-off performance, Saab XWD is capable of completely locking the front and rear axles, but can also adapt as little as 4% of torque to the rear wheels during highway cruising, thus maximizing fuel economy. To ensure immediate traction, torque distribution can be transferred to the wheel with the most grip in fractions of a second, and using the two couplings the XWD system can send 85% of available torque to a single rear wheel. The ability to transfer torque laterally between the rear wheels is similar to Mitsubishi
's Super Active Yaw Control or Honda
/Acura
's Super Handling-All Wheel Drive
.
An ECU
continuously collects various data from the car's onboard systems, and in conjunction with the ESP, ABS and TCS calculates the best torque distribution in the driveline.
The XWD system first debuted on the 2008 limited edition Saab Turbo X, equipped with an electronically controlled limited slip differential
(eLSD) and was gradually made available through the rest of the 9-3 for the 2009 model year (in sedan and combi body styles). XWD will be the standard drivetrain for the new generation Saab 9-5
, expected as a 2010 model year vehicle and will also underpin Saab's upcoming cross-over utility vehicle, the 2011 Saab 9-4X
, as well as the Saab 9-3X, an off-road modification of the 9-3 SportCombi. This XWD system is also used in Opel Insignia
.
While the Haldex Generation 4 system will be made available to other automobile manufacturers starting 2009, the XWD moniker is a trademark owned by Saab Automobile AB, and thus cannot be used by any other make.
Haldex
Haldex Traction AB is a division of the Swedish manufacturing company Haldex AB. It specialises in the development and manufacture of All-Wheel Drive systems. Haldex is currently producing their fourth generation AWD system called, by Saab, XWD . The first generation of Haldex’s four-wheel drive...
in partnership with Saab
Saab Automobile
Saab Automobile AB, better known as Saab , is a Swedish car manufacturer owned by Dutch automobile manufacturer Swedish Automobile NV, formerly Spyker Cars NV. It is the exclusive automobile Royal Warrant holder as appointed by the King of Sweden...
. Also known as Haldex Generation 4, it is an intelligent permanent all-wheel drive system that can pre-emptively and continuously change torque distribution before wheel slip occurs.
Mitsubishi Motors
is a multinational automaker headquartered in Minato, Tokyo. In 2009 it was the fifth-largest Japan-based automaker and the 17th-largest in the world measured by production...
's Super Active Yaw Control or Honda
Honda
is a Japanese public multinational corporation primarily known as a manufacturer of automobiles and motorcycles.Honda has been the world's largest motorcycle manufacturer since 1959, as well as the world's largest manufacturer of internal combustion engines measured by volume, producing more than...
/Acura
Acura
Acura is the luxury vehicle division of Japanese automaker Honda Motor Company. The brand has been available in the United States and Canada since March 1986, marketing luxury, performance, and near-performance vehicles. It was introduced to Hong Kong in 1991, Mexico in 2004, and China in 2006...
's Super Handling-All Wheel Drive
SH-AWD
Super Handling-All Wheel Drive or SH-AWD is a full-time, fully automatic all-wheel drive traction and handling system designed and engineered by Honda Motor Company. The system was announced in April 2004, and first introduced in the North American market in the second generation 2005 model year...
.
An ECU
Electronic control unit
In automotive electronics, electronic control unit is a generic term for any embedded system that controls one or more of the electrical systems or subsystems in a motor vehicle....
continuously collects various data from the car's onboard systems, and in conjunction with the ESP, ABS and TCS calculates the best torque distribution in the driveline.
The XWD system first debuted on the 2008 limited edition Saab Turbo X, equipped with an electronically controlled limited slip differential
Limited slip differential
A limited slip differential is a type of differential gear arrangement that allows for some difference in angular velocity of the output shafts, but imposes a mechanical bound on the disparity...
(eLSD) and was gradually made available through the rest of the 9-3 for the 2009 model year (in sedan and combi body styles). XWD will be the standard drivetrain for the new generation Saab 9-5
Saab 9-5
The Saab 9-5 is an executive car produced by the Swedish automobile maker Saab. The first generation was introduced in 1997 as the replacement to the Saab 9000 for the 1998 model year. At the time, the car represented a great leap forward for Saab...
, expected as a 2010 model year vehicle and will also underpin Saab's upcoming cross-over utility vehicle, the 2011 Saab 9-4X
Saab 9-4X
The Saab 9-4X is a mid-size crossover SUV introduced by Swedish automaker Saab Automobile at the LA Auto Show 2010. It is based on the all-wheel drive GM Theta Premium platform. The 9-4X will begin production in 2011 and is scheduled to be built at Ramos Arizpe, Mexico...
, as well as the Saab 9-3X, an off-road modification of the 9-3 SportCombi. This XWD system is also used in Opel Insignia
Opel Insignia
The Opel Insignia is a large family car engineered and produced by the German automaker Opel. Production of the Insignia began in 2008 as a replacement for the Opel Vectra. Opel launched the vehicle at the 2008 British International Motor Show in London as the Vauxhall Insignia, reflecting the...
.
While the Haldex Generation 4 system will be made available to other automobile manufacturers starting 2009, the XWD moniker is a trademark owned by Saab Automobile AB, and thus cannot be used by any other make.