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60-624: The 'mechanical' ATTESA system was developed for transverse , or front-wheel-drive vehicles and was first introduced with the RNU12 Bluebird in the Japanese market, entering production in September 1987. The system ran right throughout the U12 series (RNU12/HNU12) and was fitted to numerous U12 models with differing engine and transmission combinations. An almost identical system is fitted to

120-534: A force is allowed to act through a distance, it is doing mechanical work . Similarly, if torque is allowed to act through an angular displacement, it is doing work. Mathematically, for rotation about a fixed axis through the center of mass , the work W can be expressed as W = ∫ θ 1 θ 2 τ   d θ , {\displaystyle W=\int _{\theta _{1}}^{\theta _{2}}\tau \ \mathrm {d} \theta ,} where τ

180-430: A body, a torque can be thought of as a twist applied to an object with respect to a chosen point; for example, driving a screw uses torque, which is applied by the screwdriver rotating around its axis . A force of three newtons applied two metres from the fulcrum, for example, exerts the same torque as a force of one newton applied six metres from the fulcrum. The term torque (from Latin torquēre , 'to twist')

240-444: A maximum of 50:50. The drive for the front wheels comes from a transfer case bolted on the end of an almost traditional Nissan RWD transmission. A short driveshaft for the front wheels exits the transfer case on the right side. Inside the transfer case a multi-row chain drives a multi-plate wet clutch pack. Drive from the chain is apportioned using this clutch pack in the transfer case "differential" (the system thus does not involve

300-579: A regular gear differential as in a full-time 4WD layout, but rather a center clutch), similar to the type employed in the Steyr-Daimler-Puch system in the Porsche 959 . This unit is lubricated with its own dedicated NS-ATF fluid supply (Nissan Special Automatic Transmission Fluid) and is not in any way connected to the fluid in the transmission. Some Nissan models have an external cooler with an electric pump to cool this fluid. Situated on top of

360-762: A single point particle is: L = r × p {\displaystyle \mathbf {L} =\mathbf {r} \times \mathbf {p} } where p is the particle's linear momentum and r is the position vector from the origin. The time-derivative of this is: d L d t = r × d p d t + d r d t × p . {\displaystyle {\frac {\mathrm {d} \mathbf {L} }{\mathrm {d} t}}=\mathbf {r} \times {\frac {\mathrm {d} \mathbf {p} }{\mathrm {d} t}}+{\frac {\mathrm {d} \mathbf {r} }{\mathrm {d} t}}\times \mathbf {p} .} This result can easily be proven by splitting

420-584: A standard differential, not being linked to the ATTESA E-TS Pro system. The R33 Skyline regularly updates the speed of the rear wheels to the wheel speed sensors 100 times per second while the R34 Skyline regularly updates the speed of the rear wheels to the wheel sensors 1,000 times per second. The 2009 Nissan GT-R uses an updated version of the ATTESA E-TS, which is designed to work with

480-608: A transverse mounted two stroke engine, and this design was kept until the end of production, in 1991. However, it was with Alec Issigonis 's Mini , introduced by the British Motor Corporation in 1959, that the design gained acclaim. Issigonis incorporated the car's transmission into the engine's sump , producing a drivetrain unit narrow enough to install transversely in a car only 4 feet (1.2 m) wide. While previous DKW and Saab cars used small, unrefined air-cooled two-stroke engines with poor performance,

540-419: A yaw-rate feedback control system, effectively managing slip angle. Front-to-rear torque split can go from 2:98 during a standing start to a maximum of 50:50 ATTESA E-TS system is used in the following models: ATTESA E-TS Pro system is used in the following models: Transverse engine A transverse engine is an engine mounted in a vehicle so that the engine's crankshaft axis is perpendicular to

600-648: Is a general proof for point particles, but it can be generalized to a system of point particles by applying the above proof to each of the point particles and then summing over all the point particles. Similarly, the proof can be generalized to a continuous mass by applying the above proof to each point within the mass, and then integrating over the entire mass. In physics , rotatum is the derivative of torque with respect to time P = d τ d t , {\displaystyle \mathbf {P} ={\frac {\mathrm {d} {\boldsymbol {\tau }}}{\mathrm {d} t}},} where τ

660-504: Is apparent in most AWD/4WD vehicles. The advantage to a more traditional ATTESA ( Viscous LSD ) system is response in hundredths of a second. Some models fitted with the ATTESA E-TS system (such as the Nissan RS4 Stagea) have a "S" button on the dash. This will bypass the control system of the ATTESA E-TS computer and lock the transfer case into full 4WD. This is to be used at low speeds in snowy/icy conditions only as understeer

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720-459: Is better to use a term which treats this action as a single definite entity than to use terms like " couple " and " moment ", which suggest more complex ideas. The single notion of a twist applied to turn a shaft is better than the more complex notion of applying a linear force (or a pair of forces) with a certain leverage. Today, torque is referred to using different vocabulary depending on geographical location and field of study. This article follows

780-762: Is determined by the right-hand rule. Therefore any force directed parallel to the particle's position vector does not produce a torque. The magnitude of torque applied to a rigid body depends on three quantities: the force applied, the lever arm vector connecting the point about which the torque is being measured to the point of force application, and the angle between the force and lever arm vectors. In symbols: τ = r × F ⟹ τ = r F ⊥ = r F sin ⁡ θ {\displaystyle {\boldsymbol {\tau }}=\mathbf {r} \times \mathbf {F} \implies \tau =rF_{\perp }=rF\sin \theta } where The SI unit for torque

840-400: Is disengaged. This means that for general driving, the system is FWD only. When the computer detects slippage of the front wheels, the viscous coupling engages and transfers up to 50% of the torque to the rear wheels. This system is superior in some aspects since the standard operation is FWD there is less power lost due to friction. However, it is no longer a full-time 4WD system, and since

900-554: Is greatly increased in this mode. In 1995, with the introduction of the R33 Skyline GT-R, Nissan introduced a new version of their ATTESA system. It was named ATTESA-ETS Pro, as an upgrade from the earlier ATTESA-ETS. It was standard equipment in the R33 & R34 Skyline GT-R V.spec (Victory Specification) model, and was offered as an option on the standard Skyline GT-R models called the "Active LSD option". The active rear LSD

960-517: Is not restricted to such designs and has also been used on armoured fighting vehicles to save interior space. The Critchley light car , made by the Daimler Motor Company in 1899, had a transverse engine with belt drive to the rear axle. The first successful transverse-engine cars were the two-cylinder DKW F1 series of cars, which first appeared in 1931. During WWII, transverse engines were developed for armored vehicles, with

1020-571: Is said to have been suggested by James Thomson and appeared in print in April, 1884. Usage is attested the same year by Silvanus P. Thompson in the first edition of Dynamo-Electric Machinery . Thompson motivates the term as follows: Just as the Newtonian definition of force is that which produces or tends to produce motion (along a line), so torque may be defined as that which produces or tends to produce torsion (around an axis). It

1080-425: Is the moment of inertia of the body and ω is its angular speed . Power is the work per unit time , given by P = τ ⋅ ω , {\displaystyle P={\boldsymbol {\tau }}\cdot {\boldsymbol {\omega }},} where P is power, τ is torque, ω is the angular velocity , and ⋅ {\displaystyle \cdot } represents

1140-405: Is the newton-metre (N⋅m). For more on the units of torque, see § Units . The net torque on a body determines the rate of change of the body's angular momentum , τ = d L d t {\displaystyle {\boldsymbol {\tau }}={\frac {\mathrm {d} \mathbf {L} }{\mathrm {d} t}}} where L is the angular momentum vector and t

1200-410: Is the rotational analogue of linear force . It is also referred to as the moment of force (also abbreviated to moment ). The symbol for torque is typically τ {\displaystyle {\boldsymbol {\tau }}} , the lowercase Greek letter tau . When being referred to as moment of force, it is commonly denoted by M . Just as a linear force is a push or a pull applied to

1260-1748: Is time. For the motion of a point particle, L = I ω , {\displaystyle \mathbf {L} =I{\boldsymbol {\omega }},} where I = m r 2 {\textstyle I=mr^{2}} is the moment of inertia and ω is the orbital angular velocity pseudovector. It follows that τ n e t = I 1 ω 1 ˙ e 1 ^ + I 2 ω 2 ˙ e 2 ^ + I 3 ω 3 ˙ e 3 ^ + I 1 ω 1 d e 1 ^ d t + I 2 ω 2 d e 2 ^ d t + I 3 ω 3 d e 3 ^ d t = I ω ˙ + ω × ( I ω ) {\displaystyle {\boldsymbol {\tau }}_{\mathrm {net} }=I_{1}{\dot {\omega _{1}}}{\hat {\boldsymbol {e_{1}}}}+I_{2}{\dot {\omega _{2}}}{\hat {\boldsymbol {e_{2}}}}+I_{3}{\dot {\omega _{3}}}{\hat {\boldsymbol {e_{3}}}}+I_{1}\omega _{1}{\frac {d{\hat {\boldsymbol {e_{1}}}}}{dt}}+I_{2}\omega _{2}{\frac {d{\hat {\boldsymbol {e_{2}}}}}{dt}}+I_{3}\omega _{3}{\frac {d{\hat {\boldsymbol {e_{3}}}}}{dt}}=I{\boldsymbol {\dot {\omega }}}+{\boldsymbol {\omega }}\times (I{\boldsymbol {\omega }})} using

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1320-451: Is torque, and θ 1 and θ 2 represent (respectively) the initial and final angular positions of the body. It follows from the work–energy principle that W also represents the change in the rotational kinetic energy E r of the body, given by E r = 1 2 I ω 2 , {\displaystyle E_{\mathrm {r} }={\tfrac {1}{2}}I\omega ^{2},} where I

1380-818: Is torque. This word is derived from the Latin word rotātus meaning 'to rotate', but the term rotatum is not universally recognized but is commonly used. There is not a universally accepted lexicon to indicate the successive derivatives of rotatum, even if sometimes various proposals have been made. Using the cross product definition of torque, an alternative expression for rotatum is: P = r × d F d t + d r d t × F . {\displaystyle \mathbf {P} =\mathbf {r} \times {\frac {\mathrm {d} \mathbf {F} }{\mathrm {d} t}}+{\frac {\mathrm {d} \mathbf {r} }{\mathrm {d} t}}\times \mathbf {F} .} Because

1440-506: Is valid for any type of trajectory. In some simple cases like a rotating disc, where only the moment of inertia on rotating axis is, the rotational Newton's second law can be τ = I α {\displaystyle {\boldsymbol {\tau }}=I{\boldsymbol {\alpha }}} where α = ω ˙ {\displaystyle {\boldsymbol {\alpha }}={\dot {\boldsymbol {\omega }}}} . The definition of angular momentum for

1500-624: Is zero because velocity and momentum are parallel, so the second term vanishes. Therefore, torque on a particle is equal to the first derivative of its angular momentum with respect to time. If multiple forces are applied, according Newton's second law it follows that d L d t = r × F n e t = τ n e t . {\displaystyle {\frac {\mathrm {d} \mathbf {L} }{\mathrm {d} t}}=\mathbf {r} \times \mathbf {F} _{\mathrm {net} }={\boldsymbol {\tau }}_{\mathrm {net} }.} This

1560-533: The Nissan FM platform (which are sold in certain markets under the Infiniti luxury brand). The ATTESA E-TS version uses a mostly conventional RWD transmission. Drive to the rear wheels is constant via a tailshaft and rear differential , but drive to the front wheels is more complex by utilizing a transfer case on the rear of the transmission. Front-to-rear torque split can go from 0:100 during acceleration to

1620-635: The Yellow Coach 719, using Dwight Austin's V-drive; they continued in common use until the 1990s, though shorter V-configuration engines in a longitudinal "T-drive" configuration became common in the 1960s. Transverse engines were also used in the British Leyland Atlantean , in many transit buses, and in nearly all modern double decker buses . They have also been widely used by Scania , MAN , Volvo and Renault 's bus divisions. Engines may be placed in two main positions within

1680-421: The lever's fulcrum (the length of the lever arm ) is its torque. Therefore, torque is defined as the product of the magnitude of the perpendicular component of the force and the distance of the line of action of a force from the point around which it is being determined. In three dimensions, the torque is a pseudovector ; for point particles , it is given by the cross product of the displacement vector and

1740-414: The scalar product . Algebraically, the equation may be rearranged to compute torque for a given angular speed and power output. The power injected by the torque depends only on the instantaneous angular speed – not on whether the angular speed increases, decreases, or remains constant while the torque is being applied (this is equivalent to the linear case where the power injected by a force depends only on

1800-452: The 1960s, are said to have "transverse" engines, while motorcycles with a V-twin mounted with its crankshaft perpendicular to the direction of travel, e.g. most Ducatis since the 1970s and most Harley-Davidsons , are said to have "longitudinal" engines. This convention uses the longest horizontal dimension (length or width) of the engine as its reference axis instead of the crankshaft. Torque In physics and mechanics , torque

1860-532: The ABS system. The computer can then direct up to 50% of the power to the front wheels. When slip is detected on one of the rear wheels (a rear wheel turn 5% or more than the front wheels), the system directs torque to the front wheels which run a non-limited slip differential. Rather than locking the AWD in all the time or having a system that is "all or nothing", the ATTESA E-TS system can apportion different torque ratios to

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1920-619: The RNN14 GTi-R Pulsar and the HNU13 Bluebird and the HNP10 Primera , finding usage in numerous other Nissan models. Quite similar to offerings from other manufacturers, drive passes from the gearbox to a center viscous limited slip differential , into a transfer case splitting drive to a co-located front differential, and tail shaft connected to the vehicle's rear differential . From 2000 model year onwards,

1980-611: The Soviet T-44 and T-54/T-55 tanks being equipped with transverse engines to save space within the hull. The T-54/55 eventually became the most produced tank in history. After the Second World War , Saab used the configuration in their first model, the Saab 92 , in 1947. The arrangement was also used for Borgward 's Goliath and Hansa brand cars. The East German -built Trabant , which appeared in 1957, also had

2040-721: The above expression for work, , gives W = ∫ s 1 s 2 F ⋅ d θ × r {\displaystyle W=\int _{s_{1}}^{s_{2}}\mathbf {F} \cdot \mathrm {d} {\boldsymbol {\theta }}\times \mathbf {r} } The expression inside the integral is a scalar triple product F ⋅ d θ × r = r × F ⋅ d θ {\displaystyle \mathbf {F} \cdot \mathrm {d} {\boldsymbol {\theta }}\times \mathbf {r} =\mathbf {r} \times \mathbf {F} \cdot \mathrm {d} {\boldsymbol {\theta }}} , but as per

2100-479: The car's rear transaxle layout. The system is unique in the way that it utilizes two driveshafts under the vehicle's centerline, with a second driveshaft running slightly to the right of the main driveshaft which transfers power to the front wheels. Unlike the previous ATTESA systems which relied heavily on mechanical feedback, the system in the GT-R uses electronic sensors and hydraulically actuated clutches. It also has

2160-435: The coupling is in the rear differential, the driveshaft itself is constantly driven even though it is not connected to anything, which saps some power and efficiency (the analogue being the front driveshaft of a part-time 4x4 truck without locking hubs ). The Electronic Torque Split version of this all-wheel drive architecture is a more advanced system developed for Nissan vehicles with a longitudinal drive train layout. It

2220-439: The definition of torque, and since the parameter of integration has been changed from linear displacement to angular displacement, the equation becomes W = ∫ θ 1 θ 2 τ ⋅ d θ {\displaystyle W=\int _{\theta _{1}}^{\theta _{2}}{\boldsymbol {\tau }}\cdot \mathrm {d} {\boldsymbol {\theta }}} If

2280-605: The definition used in US physics in its usage of the word torque . In the UK and in US mechanical engineering , torque is referred to as moment of force , usually shortened to moment . This terminology can be traced back to at least 1811 in Siméon Denis Poisson 's Traité de mécanique . An English translation of Poisson's work appears in 1842. A force applied perpendicularly to a lever multiplied by its distance from

2340-411: The derivative of a vector is d e i ^ d t = ω × e i ^ {\displaystyle {d{\boldsymbol {\hat {e_{i}}}} \over dt}={\boldsymbol {\omega }}\times {\boldsymbol {\hat {e_{i}}}}} This equation is the rotational analogue of Newton's second law for point particles, and

2400-441: The direction of travel. Many modern front-wheel drive vehicles use this engine mounting configuration. Most rear-wheel drive vehicles use a longitudinal engine configuration, where the engine's crankshaft axis is parallel with the direction of travel, except for some rear-mid engine vehicles, which use a transverse engine and transaxle mounted in the rear instead of the front. Despite typically being used in light vehicles, it

2460-485: The engine to its gearbox by a shaft and set the differential off-center so that it could be connected to the gearbox more easily. The half shafts from the differential to the wheels therefore differed in length, which would have made the car's steering asymmetrical were it not for their torsional stiffness being made the same. Giacosa's layout was first used in the Autobianchi Primula in 1964 and later in

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2520-468: The engine's sump to the left wheel. To control the ATTESA E-TS system, there is a 16-bit computer that monitors the cars movements 10 times per second to sense traction loss by measuring the speed of each wheel via the ABS sensors. Also a three-axis G-Sensor mounted underneath the center console feeds lateral and longitudinal inputs into a computer, which controls both the ATTESA-ETS AWD system and

2580-454: The force vector. The direction of the torque can be determined by using the right hand grip rule : if the fingers of the right hand are curled from the direction of the lever arm to the direction of the force, then the thumb points in the direction of the torque. It follows that the torque vector is perpendicular to both the position and force vectors and defines the plane in which the two vectors lie. The resulting torque vector direction

2640-488: The front wheels as it sees fit. This provides the driver with an AWD vehicle that performs like a rear wheel drive vehicle in perfect conditions and can recover control when conditions aren't as perfect. From the factory, the system is set up to provide slight oversteer in handling, and in fact the harder the car is cornered, the LESS the AWD system engages the front wheels. This promotes the oversteer rather than understeer which

2700-438: The front wheels to be varied. Exiting the transfer case, the front drive shaft runs along the right side of the transmission, into a differential located on the right of the engines sump. This is a cast aluminum unit, with the sump and front differential made as a single unit that cannot be separated. The front right axle is shorter than the left, because the differential is closer to the right wheel. The front left axle runs through

2760-541: The gearbox-in-sump arrangement meant that an 848 cc four-cylinder water-cooled engine could be fitted to the Mini, providing strong performance for a car of its size. Coupled to the much greater amount of interior space afforded by the layout (the entire drivetrain only took up 20% of the car's length), this made the Mini a genuine alternative to the conventional small family car. This design reached its peak starting with Dante Giacosa 's elaboration of it for Fiat . He connected

2820-568: The infinitesimal linear displacement d s {\displaystyle \mathrm {d} \mathbf {s} } is related to a corresponding angular displacement d θ {\displaystyle \mathrm {d} {\boldsymbol {\theta }}} and the radius vector r {\displaystyle \mathbf {r} } as d s = d θ × r {\displaystyle \mathrm {d} \mathbf {s} =\mathrm {d} {\boldsymbol {\theta }}\times \mathbf {r} } Substitution in

2880-586: The instantaneous speed – not on the resulting acceleration, if any). The work done by a variable force acting over a finite linear displacement s {\displaystyle s} is given by integrating the force with respect to an elemental linear displacement d s {\displaystyle \mathrm {d} \mathbf {s} } W = ∫ s 1 s 2 F ⋅ d s {\displaystyle W=\int _{s_{1}}^{s_{2}}\mathbf {F} \cdot \mathrm {d} \mathbf {s} } However,

2940-520: The motor car: Space allowed for engines within the front wheel wells is commonly limited to the following: The description of the orientation of V-twin and flat-twin motorcycle engines sometimes differs from the convention as stated above. Motorcycles with a V-twin engine mounted with its crankshaft parallel to the direction of travel, e.g. the AJS S3 V-twin , Indian 841 , Victoria Bergmeister , Honda CX series and several Moto Guzzis since

3000-441: The popular Fiat 128 . With the gearbox mounted separately to the engine, these cars were by necessity larger than the Mini, but this proved to be no disadvantage. This layout, still in use today, also provided superior refinement, easier repair and was better-suited to adopting five-speed transmissions than the original Issigonis in-sump design. The Lamborghini Miura used a transverse mid-mounted 4.0-litre V12 . This configuration

3060-528: The rate of change of force is yank Y {\textstyle \mathbf {Y} } and the rate of change of position is velocity v {\textstyle \mathbf {v} } , the expression can be further simplified to: P = r × Y + v × F . {\displaystyle \mathbf {P} =\mathbf {r} \times \mathbf {Y} +\mathbf {v} \times \mathbf {F} .} The law of conservation of energy can also be used to understand torque. If

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3120-456: The rear differential is a high pressure, low volume electric pump. This pump pressurizes Normal ATF (0-288 psi) into the transfer case to engage the clutch pack. This fluid only engages the clutch pack and does not mix with the NS-ATF lubricating the transfer case. The higher the fluid pressure the transfer case is supplied with from the pump, the more the clutch pack engages, enabling the torque to

3180-433: The system received an update where, as with a typical FWD car, the transaxle now contained a differential that drives the front wheels. However, an extra shaft from this differential also drives a bevel gear housed in the transfer case that permanently turns a driveshaft for the rear wheels (i.e. there is no longer a "center" differential). Housed in the rear differential is a viscous coupling that in normal conditions

3240-875: The torque and the angular displacement are in the same direction, then the scalar product reduces to a product of magnitudes; i.e., τ ⋅ d θ = | τ | | d θ | cos ⁡ 0 = τ d θ {\displaystyle {\boldsymbol {\tau }}\cdot \mathrm {d} {\boldsymbol {\theta }}=\left|{\boldsymbol {\tau }}\right|\left|\mathrm {d} {\boldsymbol {\theta }}\right|\cos 0=\tau \,\mathrm {d} \theta } giving W = ∫ θ 1 θ 2 τ d θ {\displaystyle W=\int _{\theta _{1}}^{\theta _{2}}\tau \,\mathrm {d} \theta } The principle of moments, also known as Varignon's theorem (not to be confused with

3300-733: The vectors into components and applying the product rule . But because the rate of change of linear momentum is force F {\textstyle \mathbf {F} } and the rate of change of position is velocity v {\textstyle \mathbf {v} } , d L d t = r × F + v × p {\displaystyle {\frac {\mathrm {d} \mathbf {L} }{\mathrm {d} t}}=\mathbf {r} \times \mathbf {F} +\mathbf {v} \times \mathbf {p} } The cross product of momentum p {\displaystyle \mathbf {p} } with its associated velocity v {\displaystyle \mathbf {v} }

3360-616: The vehicle. This has also allowed for improved safety in a frontal impact, due to more longitudinal engine compartment space being created. The result is a larger front crumple zone . Transverse engines have also been widely used in buses. In the United States, they were offered in the early 1930s by Twin Coach and used with limited success in Dwight Austin's Pickwick Nite-Coach. Transverse bus engines first appeared widely in

3420-582: Was also available as an option on some rear wheel drive Nissans such as the R33 GTS25t, the C34 RS Stagea and Y33 Cima S-Four.. ATTESA E-TS Pro differs from the standard ATTESA E-TS in a few ways. Where ATTESA E-TS controls the front to rear torque-split, the Pro system is also capable of left-and-right torque split to the rear wheels. This is done via an active rear LSD . Additionally, ATTESA E-TS Pro

3480-734: Was first used in August 1989 in the R32 Nissan Skyline GT-R and Nissan Skyline GTS-4 . Although the Skyline GT-R is exclusively AWD with manual transmission, ATTESA E-TS is also used in Nissan models that are available as rear wheel drive (RWD) with automatic transmissions fitted, such as the A31 Nissan Cefiro which was the second Nissan to feature the system exactly a year later in August 1990, and vehicles based on

3540-408: Was marketed as controlling the ABS system to each wheel independently, while the previous ABS computer could sense the speed of each wheel its ABS pump is only 3-channel (both rear brakes are linked as a pair). Although this is not part of the AWD system, the computer makes use of the same sensors to determine wheel slip and traction. On ATTESA E-TS Pro equipped vehicles, the front differential remains

3600-471: Was unheard of in 1965, but became more common in the following decades, with cars such as the Lancia Montecarlo , Noble M12 , Toyota MR2 , Pontiac Fiero , and first-generation Honda NSX using such a powertrain design. The Land Rover LR2 Freelander , along with all Volvo models from 1998 on (including V8 models), employ a transversely-mounted engine in order to increase passenger space inside

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