Quattro (meaning four in Italian) is a sub-brand used by Audi brand cars to indicate that a technology or all-wheel drive (AWD) system is used on certain car models Audi. This is also the actual performance division of Audi with S and RS.
The word "quattro" is a registered trademark of Audi AG, a subsidiary of German automotive concern, Volkswagen Group.
The Quattro was first introduced in 1980 on the permanent Audi Quattro four-wheel drive model, often referred to as the Ur-Quattro ("Ur-" is the German prefix meaning "original" or "first"). The term quattro has been applied to all subsequent Audi AWD models. Since the nomenclature right is derived from the trademark, the word quattro is now always spelled in lowercase "q" , in honor of its first name.
Other companies in the Volkswagen Group have used different trademarks for their 4WD vehicles. While Audi always uses the term "quattro", the Volkswagen branded car originally used "syncro" , but recently, VW used "4motion" . ? koda only uses the "4x4" nomenclature after the model name, whereas SEAT only uses "4" ( "4Drive" recently). None of the above trademarks or nomenclatures define the operation or type 4WD system, as described below.
Video Quattro (four-wheel-drive system)
Longitudinal system
Volkswagen Group has developed a four-wheel drive system (4WD) almost since its inception during the Second World War. Volkswagen KÃÆ'¼belwagen, Volkswagen Schwimmwagen, and Volkswagen Kommandeurswagen are all military vehicles that require all four wheels of the road to be "driven", the latter being the Volkswagen Beetle 4WD. Their military experience and four-wheeled vehicles then helped them design the Volkswagen Iltis for the German military (Bundeswehr) in the 1970s. Iltis utilizes the initial 4WD form, which will later become synonymous with "quattro".
Lockout center preview
In the original quattro system, which was later found in passenger cars running on the road, the engine and transmission were in a longitudinal position. The torque is transmitted through the transmission to a mechanical center differential (commonly abbreviated as "diff") that divides (distributes) the torque between the front and rear axles. 4WD is permanently active.
The Torsen T1 center differential
After 1987, Audi replaced the locking of the locking center manually with Torsen center sensing (torque sensing) Type 1 ("T1"). This allows the engine torque to automatically be directed to individual axles as driving conditions, and the grip is guaranteed. Under 'normal' conditions (where the grip on the front and rear axle is the same), the torque is split between front and back with a 50:50 'default' distribution in many, though not all, versions. Under adverse conditions (ie, when there is a variation of the grip between front and back), a maximum of 67-80% (depending on transmission, or Torsen diff model) of engine torque can be directed to the front or rear axle. The fully automated mechanical properties of the Torsen center difference help prevent the wheel deterioration from occurring, by diverting the torque directly, without clear notice to the passenger of the vehicle, to the shaft which has more grip. This method of operation can be described as proactive. Furthermore, unlike many different types of electronically operated differentials, Torsen has no requirements for electronic data, from sources such as wheel speed sensors, therefore, having a "safe fail" element, unlike designs such as Haldex Traction, must be wrong one wheel spee d sensor developed an error. In comparison, the viscous coupling, and electronically controlled differential center used in other four-wheel drive systems are reactive, since they only redirect torque after a wheel slip occurs. The advantage feels under hard acceleration, including when cornering, because the torque displacement between the axle smooth, thus maintaining the dynamics of a stable vehicle, and greatly reduce the possibility of losing control of the vehicle.
The Torsen-based quattro system also offers advantages, in the opposite function of distributing torque to the road wheel, ie engine braking. When engine braking is used to slow the car down, with a Torsen-based system, the "torque back" load generated on the front and rear axles is equally stable, in exactly the same way as "engine propulsion" torque is mechanically dispensed entirely independently. This allows the spread of braking effects to all wheels and tires. The Torsen quattro-based vehicle is capable of running a more stable high speed round below deceleration, with less risk of losing control due to loss of grip on the front or rear axle.
This quattro system configuration, however, does have some limitations:
- With engine placement and transmission assemblies in front/rear (longitudinal) position, the front axle is placed behind the engine, leading to criticism of some Audi vehicles as a heavy nose, although the system still leads to distribution better weight than the machine package that is installed in transverse like in Mitsubishis and similar cars. This allows the weight distribution to be better than 55:45 (F: R).
- Torsen's natural nature resembles a limited slip differential in that case, rather than actively allocating torque (as a computer controlled clutch), it supports differential torque across (differential torque/TBR ratio)), from the side with the least handles to the sides with the most. Therefore, Torsen is naturally limited in the amount of torque that can be supplied to the axle with most grips by the available torque on the axle with the number of handles at least . Therefore, if one axle has no grasp, regardless of TBR, other axles will not be supplied with great torque. In the extreme, for a central differential implementation, complete traction loss on a single wheel will produce very limited torque to the other three wheels. Audi responded to this limitation for the first Torsen-equipped car by adding manual rear-lock differentials and then replacing this feature with Electronic Differential Lock (EDL), which is the ability to use individual wheel brakes (monitored by ABS sensors) to limit the rotation of individual wheels. EDL is implemented in both front and back differential (open) to operate at speed & lt; 80 km/h. It has the effect of increasing the torque from a single low-traction wheel thereby allowing more torque to be passed by the Torsen to the remaining high-traction wheels.
- While Torsen's standard (Type 1 or T1 ) supports a static torque ratio of 50:50; ie, the input torque is supported evenly on both output shafts, T1 has a Torque Bias Ratio (TBR) of 2.7-4: 1; ie, allowing about 3 to 4 times the torque to be supplied to most traction output shafts rather than those available on most traction shafts or, torque splits between 25% to 75%. However, naturally T1 Torsen is locked under most circumstances (the output shaft is locked together). Only when TBR is achieved (ie, there is a greater torsion difference across the output shaft than can be supported by TBR) do the output shaft turn relative to each other, and the differential unlocks. This characteristic produces a relatively free torque movement between the two outputs of the differential (center), within the limits of TBR. So the Torsen T1 static torque distribution in the central differential installation, rather than 50:50, will reflect the weight distribution (both static and dynamic) of the vehicle due to the traction available on the output shaft (front: rear). In standard cars, this is desirable from the perspective of stability, acceleration and traction, but can be undesirable in terms of handling (understeer). While the standard Torsen T1 quattro with 2.7: 1 TBR is more than adequate in most conditions, the Torsen T1 differential with higher TBR (4: 1) is available and can further limit the understeer by supporting wider torque splits. However, a better solution is to divide the torque directly between the two output shafts (front & rear) and for this reason Audi has adopted the Torsen Type 3 design ( T3 ) on the latest generation of quattro.
Torsen Type "C" (T3) )
The Torsen T3 differential center incorporates a set of planetary gear with a Torsen differential in a compact package developed for central differential installation. In contrast to the Torsen T2 where the torque split is 50:50 nominal, at T3 Torsen the torque split, due to the use of the planetary gear set, is asymmetric 40:60 actual front-rear torque split (ie, when the handle is the same on the front and rear axles, 40 % torque delivered to front axle, and 60% back). Like the Torsen T1, the torque will be dynamically distributed depending on the traction conditions, but with the actual static bias (not nominal). T3 allows handling characteristics and vehicle dynamics more similar to rear-wheel drive cars. This asymmetrical torsen was first introduced on the highly reputed Audi RS4 2006 model (B7). Type 3 torsen was used in Audi S4 and RS4 B7 manual transmissions from 2006 to 2008, as well as models S6, S8, and Q7 from 2007.
The torque splitting the axle, between the left and right wheels, has been achieved through various evolutions of the quattro system, through a driver-selectable driver lock differential (just a rear axle), and, finally, through open differential with Electronic Differential Lock (EDL). EDL is an electronic system, utilizing the existing anti-lock braking system (ABS), part of the Electronic Stability Program (ESP), which brakes only one wheel that rotates on the shaft, allowing torque transfer across the axle to the wheel that does have an appeal.
The center difference of the steering wheel
Audi debuted a new generation of quattro in 2010 RS5. The main change was the replacement of the Torsen Type "C" differential center with the differential "Crown Gear" developed by Audi. While this is superficially the same as the normal Open differential, which is adapted for central applications, it has several key differences:
- The center drive and spider gear interface are directly linked to the two crown wheels connected to the front and rear drive shaft
- Two crowns of the interface wheel to spider gears at different diameters, resulting in different torques when reversed by the spider wheel. It's engineered to produce static splits of 40:60 front and rear torque.
- Each of the crown wheels interfaces to each output shaft directly, while the spider carrier interface for each output shaft uses a clutch package that gives the unit the ability to control the torque distribution above and above the static torque distribution.
If one shaft loses the handle, different rotational speeds appear within the differential resulting in an increase in the axial force which forces the clutch plate to close. Once closed, the output shaft is locked so that the transfer of the majority of torque to the shaft achieves better traction. In Crown Gear differentials up to 85% of the torque can flow backwards, and up to 70% of the torque can be switched to the front axle.
Features of Crown Gear differentials provide the following benefits over Torsen Type "C"
- Ability to set a more stable torque distribution, with full locking whereas Torsen can only provide torque distribution to Torque Bias Ratio; eg, Crown Gear differentials can lock completely, regardless of the bias ratio. Unlike the Torsen, Crown Gear differential does not operate like a limited slip differential and can operate, fully locked, without traction on a single output shaft.
- Easier integration into control electronics that enables 4-wheel electronic torque vectors with or without active backbone differential
- Reduced size and weight is quite large (4.8 kg, about 2 kg lighter than Torsen Type C)
The net result of advances in quattro is the vehicle's electronic capability to fully manage the vehicle dynamics in all traction situations, whether in cornering, acceleration or braking or in this combination.
Evolutions
Audi has never officially debuted quattro in certain generations - changes to quattro technology generally have started with a range or a particular model in the range and then taken to other models as long as the corresponding points in the model cycle.
The exceptions above are the debut of RS5 2010 which, inter alia, is heralded by Audi as the debut of a new generation of quattro.
Generation Quattro I
Used from 1981 to 1987 on Audi Quattro turbo coupÃÆ'Â ©, Audi 80 B2 platform (1978-1987, Audi 4000 in the North American market), Audi CoupÃÆ' Â © quattro platform B2 (1984-1988), Audi 100 C3 platform (1983- 1987, Audi 5000 in North American market). Also, starting from 1984, used on the Volkswagen platform VW Passat B2 (VW Quantum on the US market) where it is known as Syncro .
System type: Permanent four wheel drive.
Open center differential, can be manually locked via a switch on the center console.Ã,¹
Open the rear differential, can be locked manually via the switch on the center console.Ã,¹
Open the front differential, no lock.
Ã,¹ABS is disabled when locked.
How the system performs: When all differences are opened, the car will not move if one wheel (front or rear) loses traction (either on the ice or raised in the air). When the central differential is locked with the rear differential opened, the car will not be able to move if one front wheel and one rear wheel lose traction. When the rear differential is locked with the lock open, the car will not move if two tears or one front part lose its appeal. When both the central and rear differentials are locked, the car will not be able to move if two tears and one loses front traction.
Quattro II Generation
Starting from 1988 on the older generation Audi 100 C3 platform and Audi Quattro to the end of their production, and on the new generation B3 platform (1989-1992) Audi 80/90 quattro, B4 platform (1992-1995) Audi 80, Audi S2 , Audi RS2 Avant, C4 platform (1991-1994) Audi 100 quattro, Audi S4, then platform C4 (1994-1997) Audi A6/S6.
System type: Permanent four wheel drive.
Torsen center differential, 50:50 'default' split, automatically split up to 75% torque transfer to one axle.
Open the rear differential, can be locked manually via the switch on the center console located next to the handbrake. ¹
Open the front differential, no lock.
Ã,¹ABS is disabled when locked, it automatically opens if speed exceeds 25 km/h (16 mph).
Quattro generation III
Used only in Audi V8 from 1988 to 1994.
System type: Permanent four wheel drive.
V8 with automatic transmission :
Differential differential planetary gears with electronically controlled multi-plate locking couplings
Torsen type 1 differential rear.
Open front differential.
V8 with manual transmission :
Torsen type 1 central differential.
Torsen type 1 rear differential.
Open the front differential.
How the system performance: In the conditions on the road, the car will not be able to move if one front wheel and two rear wheels lose traction altogether.
Quattro IV Generation
Starting from 1995 at Audi A4/S4/RS4 (B5 platform), Audi A6/S6/allroad/RS6, Audi A8/S8 with manual and automatic transmission. Also on VW Passat B5, where it was originally referred to as syncro , but by the time it reached US soil, it has resurrected 4motion. Also used on Volkswagen's Phaeton and Volkswagen Group D sister vehicles platform. Volkswagen Touareg uses 4Xmotion with separate transmission, PTUs and front axle.
The manual differential rear locks of previous generations are replaced by conventional open differentials, with Electronic Differential Lock (EDL) (which detects wheelpin through an ABS road wheel speed sensor), and apply the brakes to a rotating wheel, thereby transferring torque through an open differential to the wheel opposite that has more traction). EDL works at speeds of up to 80 km/h (50 mph) on all quattro models (on non-quattro models: up to 40 km/h (25 mph).
System type: Permanent four wheel drive.
Torsen type 1 or 2 center differential, 50:50 'default' split, automatically split up to 75% torque transfer to front or rear axle.
Open the rear differential, Electronic Differential Lock (EDL).
Open the front differential, Electronic Differential Lock (EDL).
Generation Quattro V
It starts with the Audi RS4 B7 and a manual transmission version of the Audi B7 2006 S4. It was adopted throughout the S4, S6, and S8 lineup in 2007.
System type: Asymmetrical four-wheel drive permanent.
Torsen type 3 (Type "C") center differential, 40:60 'default' split front-rear, automatically divides up to 80% of torque into one shaft using a high bias 4: 1 central differential. With the help of ESP, up to 100% of the torque can be transferred to one axis.
Open the rear differential, Electronic Differential Lock (EDL).
Open the front differential, Electronic Differential Lock (EDL).
System quattro Vectoring
Audi sport's new budi differentiation, debuted with torque vectoring for quattro generation V. The difference Audi sport allows dynamic allocation of torque behind the axle of the vehicle debut: B8 (2008) S4, and now optional addition to all vehicles quattro, which continues to use the Torsen 40:60 asymmetric (Type "C") differential center. The sports differential replaces the normal open back differential while the front axle still relies on an open differential with EDL.
Differential axle rear axle torque designed and manufactured by Magna Powertrain, and offered on Audi A4, A5, A6 and its derivatives (including model RS ). The Differential Sport selectively distributes torque to the rear wheel so as to produce a yaw moment, which improves handling and also stabilizes the vehicle when it is oversteer or understeer, thus improving safety.
Differential sports operate by using two superposition gears ("step up") on the differential, which are operated through a multi-plate coupling each side of the differential wheel wheel. When required by the software (using lateral and longitudinal yaw sensors, ABS wheel sensors, and steering wheel sensors), the control software (located in the control unit close to the rear differential), drives the relevant clutch. It has the effect of taking the output shaft drive through the step-up gear to the connected wheel, while the other axle keeps pushing the wheels directly (ie, the coupling package is not moved). The output shaft with higher speed results in increased torque to the wheels, resulting in a yaw (spinning) moment. In normal operation, an increase of torque is applied to the wheels beyond the turn, increasing the moment of the vehicle's turn, in other words, its willingness to turn in the direction designated by the wheel.
Quattro VI Generation
Audi debuted the 6th generation of quattro in 2010 RS5. The key change in VI generation is the replacement of the Torsen Type "C" differential center with the differential "Crown Gear" developed by Audi. With the new center differential "Crown Gear", up to 70% of torque can be applied to the front wheel while up to 85% can be applied to the rear wheels if necessary. The net result of this advancement in quattro is the vehicle's electronic capability to fully manage the vehicle dynamics in all traction situations, whether in cornering, acceleration, braking, snow or in this combination. The system was later adopted by the A7, the latest generation A6 and A8.
BorgWarner
Audi Q7, platform-mate from Volkswagen Touareg and Porsche Cayenne, does not use the same base from the previous model. BorgWarner instead provides a 4WD system for this more off-road SUV. Torsen Differential Type 3 (T3) is used.
Ultra
Audi announced "Audi Quattro with Ultra Technology" in February 2016, this is a front-wheel drive system for use on platforms with long-mounted engines, and shares many similarities with their Haldex-based systems.
Maps Quattro (four-wheel-drive system)
Transverse system
Since the mainstream main-engined vehicle Volkswagen Group in 1974, four-wheel drive (4WD) has also been considered for their A-family car platform. It was not until the second generation of this 4WD platform finally appeared on the market. Mid-1980s Mk2 Golf syncro, with transversal engine and transmission position, has most of the torque sent mainly to the front axle.
Attached to the transaxle is a Power Transfer Unit (PTU), which is connected to the rear axle through the propeller shaft. The PTU also feeds torque through itself to the front axle. On the rear axle, the torque is first sent through a thick coupling before it reaches the final mover gearset. This clutch contains friction plates and a thick enough oil so the pressure affects how many plates are connected and active (and therefore, how much power is sent to the rear wheels).
Starting with the A4-generation Mk4 platform, the viscous clutch has fallen in favor of Haldex Traction electro-hydraulic limited-slip "coupler" (LSC) or couplings. The Haldex Traction LSC unit is not a differential and therefore can not function in the actual sense as a differential. The Haldex Traction unit can switch up to 100% maximum from torque to rear axle as the conditions warrant. Many people are confused with the torque distribution on a Haldex-based system. Under normal operating conditions, Haldex coupling operates a 5% torque transmission rate. Under adverse conditions where the car's wheel drive speed sensor has determined that the two front wheels have lost traction, the Haldex clutch can lock on a 100% clamping force, meaning all torque is transferred to the rear axle. The division of torque between the left and right wheels is achieved by the conventional open differential. If one side of the driven shaft loses the handle, the Electronic Differential Lock (EDL) component of ESP controls this. EDL brakes a rotating wheel; Therefore, the torque will be transferred across the shaft to the opposite wheel through the open differential. In all transversal car engines with four wheel drive system based on Haldex, EDL only controls the front wheel, and not the rear.
The main advantages of the Haldex Traction LSC system over the Torsen-based system include: a slight gain in fuel economy (due to rear axle decoupling when not required, thus reducing driveline losses due to friction), and the ability to maintain a short engine bay and a larger passenger compartment because the engine layout is transverse. The further advantage of Haldex, when compared to the front wheel drive variant of the same model, is a more balanced front-back weight distribution (due to Haldex's "differential" center location in addition to the rear axle).
Disadvantages of the Haldex Traction system include: the vehicle has an attached front wheel handling characteristics (such as when the engine braking, the load is only applied to the front wheel, and due to the reactive nature of the Haldex system and the lag time in machine power redistribution), and the Haldex LSC unit also require additional maintenance, in the form of oil changes and filters every 60,000 kilometers (37,000 mi) (whereas Torsen is generally considered maintenance-free). Another important disadvantage of the Haldex system is the requirement for all four tires to be an identical wear rate (and the radius is scrolling), since Haldex requires data from all four wheel speed sensor sensors. The last significant disadvantage is the reduced luggage capacity in the trunk (baggage), because the large Haldex LSC unit requires an elevated boot floor of about three inches.
Condensed merger
This 4WD system is only used on Volkswagen branded vehicles, and has never been used on any Audi cars except for the Audi R8 models.
The previously mentioned viscous 4WD clutch system is found in the Transcendental Mk2 vehicle platform A2 vehicles, including Volkswagen Golf Mk2 and Jetta. It was also found in Volkswagen Type 2 (T3) (Vanagon in the US), the Mk3 Golf and Jetta generation, the third generation Volkswagen Passat B3 (based on the highly revised A-platform), and Volkswagen Eurovan.
The Vanagon RWD-bias, engine and transaxle systems are behind, while the viscous clutch is found on the front axle near the final drive. This 4WD system is known as Syncro on all vehicles.
What: Automatic four-wheel drive (on request).
A thick coupling is installed in place of a central differential, with a freewheel mechanism for breaking the shaft which is driven during braking.
Open the rear differential (optional differential mechanical lock on the Vanagon).
Open the front differential (differential mechanical lock optional on the Vanagon).
Usually a front wheel drive vehicle (except Vanagon, see above). Under normal driving conditions, 95% of the torque is transferred to the front axle. Because the thick coupling is considered "slow" (some time is required for the silicone fluid to warm up and solidify), 5% of the torque is transferred to the rear axle at any time to "pre-stress" the viscous clutch and reduce the activation time. The clutch lock when slipping occurs and up to 50% of the torque is transferred automatically to the rear axle (front in the Vanagon). Under on-road conditions, the car will not move if one front wheel and one rear wheel lose traction.
The freewheel segment, mounted inside the rear differential, allows the rear wheels to rotate faster than the front wheels without locking the viscous clutch and preventing ABS from applying the brakes to each wheel independently. Due to freewheel, the torque can be transferred to the rear axle only when the vehicle moves forward. For four-wheel drive to function when inverted, "vacuum-activated throttle" elements are mounted on a differential casing. This device locks the freewheel mechanism while in reverse gear. The freewheel mechanism will open when the transmission lever shifts to the right, past the third gear. Freewheel does not open immediately after leaving the tooth back intentionally - this prevents the freewheel from cycling from being locked to open if the car gets stuck and the driver tries to "swing" the car by changing from first to back and backwards.
The disadvantages of this four-wheel drive system are related to the actuation time of the thick clutch.
- When cornering under acceleration on a slippery surface, the rear axle is delayed, causing a sudden change in car behavior (from understeer to oversteer).
- When starting on a sandy surface, the front wheels can dig into the sand before the movers of all the wheels move.
Haldex
Starting in 1998, the Swedish Haldex Traction LSC unit replaced the thick clutch. Haldex is used by Audi on quattro versions of Audi S1, Audi A3, Audi S3, and Audi TT. It is also used by Volkswagen in the 4motion version of the Mk4 and Mk5 Volkswagen Golf, Volkswagen Jetta, and Golf R32, Volkswagen Sharan, 6th generation VW Passat (also based on A-platform) and Transporter T5. In Audis, the trademark holds, and is still referred to as quattro, while Volkswagen receives the name 4motion. The? Koda Octavia 4x4 and SEAT LeÃÆ'³n 4 and SEAT Alhambra 4 also use Haldex LSC, which is based on the Volkswagen Group model. Surprisingly, Bugatti Veyron also uses Haldex, albeit with separate transmission, PTU and front and rear axles.
What: Automatic four-wheel drive (on request).
Haldex Traction LSC multi-plate clutch with ECU electronic control, acts as a pseudo center differential.
Open back differential, no EDL.
Open the front differential, EDL.
How: Usually a front wheel drive vehicle. The Haldex Traction LSC unit can divert up to 100% of torque to the rear axle when conditions are warranted. Many people find the torque distribution in the Haldex Traction system confusing. Under normal operating conditions, Haldex LSC coupling operates at 5% (divides 5% between front and rear, and 97.5% of forward torque, and 2.5% back). Under adverse conditions where both front wheels lose traction, the Haldex clutch can lock on a 100% clamping force. This means, that since no torque is transferred to the front axle, all torque (minus losses) must be transferred to the rear axle. The division of torque between the left and right wheels is achieved by the conventional open differential. If one side of the driven shaft loses a handle, then Electronic Differential Lock (EDL) controls this. EDL brakes rotate a single wheel, and therefore the torque will be transferred to the opposite wheel through the open differential. In all transversa engine with four wheel drive system Haldex Traction LSC, EDL only control the front wheel, and not the rear.
In vehicles equipped with EDL on the front wheels only, the car will not move if the two front wheels and one rear wheels lose traction.
Again, due to the limitations of Electronic Differential Lock (see quattro IV description above), in off-road conditions sufficient for one front wheel and one rear wheel for traction loss and the car will not move.
The Haldex Traction system is more reactive than preventative, therefore there must be a slip difference (or rotation speed) of two axle systems before Haldex operates and sends torque to the rear axle. This is not the same as the spinning wheel, because the system can react less than the full rotation of the wheel on the vehicle. Torsen permanent 'full-time' even torque split in non-slipping conditions makes slipping less likely to start.
The Haldex Electronic Control Unit (ECU) releases the Haldex clutch in the middle clutch immediately after the brake is applied to allow ABS to work properly. When performing tight low-speed bends (eg, parking), the clutch is released by the Electronic Control Unit to avoid "interference" in the transmission. When the Electronic Stability Program (ESP) is activated, Haldex is released to allow the ESP system to control the vehicle effectively, this is true under acceleration and deceleration conditions.
Marketing
As part of the Audi All-Wheel Drive quattro technology celebration, the TV commercial entitled 'Ahab' was produced inspired by the American novel, Moby Dick. This ad was launched in the United States during the 2012 NFL division playoff.
See also
- 4motion - Volkswagen branded four wheel drive system.
- 4Matic - four wheel drive system from Mercedes-Benz
- All-Trac - Toyota's four wheel drive system
- ATTESA - Nissan's four wheel drive system
- S-AWC - torque all-wheel drive system from Mitsubishi Motors
- SH-AWD - drive torque all-wheel drive system from Honda
- BMW xDrive - four wheel drive system from BMW
- Four wheel drive - history of all-wheel drive in passenger car
- Symmetrical All Wheel Drive - four wheel drive system from Subaru
References
External links
- The company's international portal Audi.com
- Independent grip. Intelligent UK intelligent quattro page
Source of the article : Wikipedia
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