Lamborghini Urus

Lamborghini Urus positioning is a large-size high-performance SUV. Its length, width and height are 4990/ 1990 / 1660mm, 18 mm is longer than the Land Rover Range Rover. Urus body size is larger than the Cayenne, slightly less than the Audi Q7, which is mainly for a better handling performance.

Lamborghini Urus appearance is optimized and innovated on the base of family characteristics. Grille looks domineering. The outline of the hood and body side shows a sense of the power of SUV models demonstrated most vividly. Lamborghini URUS in shape looks like the Estoque, quite obviously tough and masculine atmosphere. It is not only equipped with 24 inches of carbon black double-spoke wheels, but also with the Aventador carbon-fiber ceramic brake system.

Urus interior continues the Lamborghini family tradition. Entire center console made from Forged Composite carbon fiber skeleton structure is throughout the interior space, and part of the area is covered by the use of leather-wrapped cushions. Four seats are covered by multiple separated cushion. Future production version may be changes and upgrades.

Urus is equipped with a 5.2L V10 naturally aspirated engine. The maximum power output is up to 584 horsepower. It is matched an 8-speed Tiptronic gearbox. In addition to traditional power version, the future is also expected to launch a hybrid version of the URUS models, maximum power output will reach 660 horsepower; in pure electric motor driven, it can achieve a maximum mileage of 25 km.

Differential & Locking Differential

There are mainly two aspects to judge how powerful a 4WD system is. One is inter-shaft power distribution system; the other, is inter-wheel power distribution systems. The former decides front and rear axles power distribution; the later decides coaxial wheel power distribution. These two contribute the SUV through capability. There are four common shaft power distribution systems: viscous couplings, multiple disk clutch, mechanical differential and transfer case.

Viscous coupling is the simplest and cheapest. Its structure is a sealed container filled with silicone oil, which has two groups slotted metal blades one connected to the front axle, one connected to the rear axle. Two groups of metal blades are separately immersed in silicone oil. It uses characteristic of silicone oil heating expansion becoming sticky for power transmission. If front wheels slip, the axles speed difference increases. The relative movement of two metal blades makes silicone oil heating, expanded, and sticky to prevent relative movement between the inner and outer panels.

Multiple disk clutch has quick response but low reliability. The differential transmits power by friction torque. There are two sets of friction discs, a group of active disks connected to the front axle, and the other group of driven disks connected to the rear axle. It is controlled by the electronic control system.

Torsen differential is agile and durable but expensive. Torsen differential, also known as torque-sensing differential, is a fully automatic purely mechanical differential, to achieve locking function fully without the aid of human or electronic systems. It has the structure of double worm turbine. Use one-way transmission of torque from the worm to the turbine to achieve differential "self-locking" feature.

Locking differential makes the differential useless. The left and right side of the wheels are connected by stiff shaft. The wheels speed is same. Even if one side of the wheels slip, the other side of the wheels can also make the car move forward, but this state cannot run in a paved road.

2WD vs. 4WD

Many people struggle when face to choose a 2-wheels drive or a 4-wheels drive SUV. If the SUV just runs in the urban areas, in order to seek the higher chassis, bigger space, only as a means of transportation to work, selecting a 2-wheels drive is sufficient. Even if you choose the four-wheels drive, basically you will not use it. In other words, you buy a four-wheels drive function for decoration, only for high cost, and high fuel consumption.

If you occasionally will play outside, you can consider a four-wheels drive. However, it is not necessary, because even the a 2-wheels drive has been able to cope with the vast majority of road conditions and weather conditions. The purpose of 4-wheels drive is not the usual "use", but to "just in case", after all, it is worthy as long as there is one time it can make you out of woods.

Four-wheels drive with all four wheels generating driving force has a higher security. If a 2-wheels drive travel in some muddy or slippery road, and the drive wheels slip, you cannot move the car. If it is a four-wheels drive encounter this situation, there are two more wheels to generate power, you can easily get rid of the trouble. In some snow or slippery roads, 4-wheels drive is not prone to slip.

In the SUV's four-wheels drive type, there are three common modes, namely, full-time 4WD, part-time 4WD, and automatic 4WD. Full-time 4WD (or permanent 4WD) means the vehicle is constantly providing power to all four wheels. Driver can enjoy the full-time maximum traction without handling it. Part-time 4WD means the driver can manually shift drive mode between 2WD and 4WD. Automatic 4WD is that system judges and make a choice for when to use a 4WD. Something needs to be noticed that full-time 4WD provides less mobility off-road than part-time 4WD does, because full-time 4WD allows a set of wheels to spin if they don't have traction. Part-time 4WD systems should not be driven on dry, smooth road surfaces when in 4WD mode, or it will soon need repairs. Automatic 4WD vehicles are not recommended for serious off-road driving. In this case, the system cannot judge wisely as human.

SUV Frame

There are two main types of frame adapted by SUVs, ladder frame and unibody. Before choosing a SUV, we should something about them. Ladder frame is very popular in the past, then more cars using a unibody construction.

The ladder frame design is simple and looks like a ladder. It consists merely of two symmetrical rails, or beams, and crossmembers. The front and rear suspension systems are connected to the wheels, while the assembly part of the engine, transmission, the body are fixed on the rigid frame. The ladder frame has continuous rails through the entire body structure. Therefore, chassis is with high strength and good resistance to bump. Even four wheels load discontinuity, it is borne by the frame, not transmitted to the body, and so the body does not easily distort. The disadvantage is that the design offers poor resistance to torsion or warping and body is relatively bulky, massive, high centroid. In general, the ladder frame has good stability and security. SUVs which focus on off-road capability will prefer it.

The unibody design is that the frame and body are constructed as a single unit. The engine, transmission, front and rear suspension and other components are fitted to the vehicle body, body load to the wheels through the suspension system. Body load is transmitted to the wheels by the suspension system.

Unibody SUVs with light weight drive smoothly in straight road. Currently selling SUV models are mainly urban types. The body structure is mostly oriented to comfort consideration. With further enhancing the vehicle manufacturing process, now unibody strength and torsional resistance have also been greatly improved. It can guarantee a comfortable city driving, and also combine off-road performance.

Buick Envision

The SUV has been introduced publicly and will go on sale in China. Its size is between Buick Encore and Buick Enclave have been made public. The car will be produced in China by Shanghai GM with a Chinese name “Ang Ke Wei”.

As a new generation of GM's global strategic models, the body shape inherited the design essence of concept car ENVISION. Overall design is dynamic, elegant and atmospheric. The front part is a straight family style chrome waterfall grille, wings style smart xenon headlights, boomerang-shaped LED daytime running lights and a streamlined exterior mirrors, creating a sharp and dynamic visual effects.

Body part is the whole window frame integrated design. Aluminum luggage rack fits the roof line. It is also equipped with 19-inch large alloy wheels. Based on General Motors platform, body size of Envision is 4667mm × 1840mm × 1659mm. Wheelbase reaches 2750mm, which will bring lavish interior space to consumers.

Envision uses a new generation of intelligent direct injection turbocharged 2.0T engine, the maximum power output is 191kW and maximum torque is 353Nm. New generation of intelligent 6-speed gearbox for the first time with the Start / Stop start-stop technology, makes the vehicle more shifting quickly and smooth. Thereby fuel consumption in urban traffic is significantly reduced. In addition, Envision is also equipped with the latest GM's four-wheel drive technology, which will greatly enhance the driving stability.

SUV Suspension System

When we mention SUVs, first thing noticed is its tough shape. The suspension system does the important work behind the scenes.

The main functions:

•  Road isolation: passengers, cargo
•  Road holding: road contact, steering, braking, acceleration
•  Cornering: counteract body roll

You inevitably meet the bumps and dips when driving. At that time the suspension plays a bog role to absorb the energy.

Nowadays popular urban SUVs mostly adapt McPherson or double-wishbone as front suspension. Rear suspensions usually are twist-beam (Buick Encore), double-wishbone (CR-V), and multi-link (VW Tiguan). If the SUV emphasizes on off-road capability, dependent suspension will be applied. Its structure is very simple, connected by a hard shaft about two wheels, and then the hard shaft connected with the body. It is more rugged therefore well suited for off-road SUVs.

McPherson suspension structure is simple less space occupied, but lack of stability. This suspension is the most common type of front suspension, mainly composed of A-type (or L-type) wishbones and damping mechanism. You can free up more space to lay out the power and electrical systems.

Twist-beam suspension takes up less space and less maintenance costs but its comfort is limited. In twist- beam suspension structure, there is no direct connection between the two wheels of the hard axis. Twist-beam can be reversed within a certain range since two wheels are connected by a torsion beam.

Double-wishbone suspension offers large lateral stiffness and good anti-roll performance. Upper and lower A-arms have two similar triangles stable structure, with sufficient torsional strength.

Multi-link suspension structure is complex, occupies a large space and provides the best comfort. It can maximize tire grip to improve vehicle handling limit.

Nissan X-Trail

The Nissan X-Trail is a compact or mid-size crossover SUV produced by the Japanese automaker Nissan since 2001. It is now considered a mid-size crossover SUV for its length gain in its third generation.

Nissan X-Trail design concept is located in the "city four-wheel drive". This is the result of Nissan's constantly subdividing markets and adjustment. From the design point of view, this car is a compromise of the market. At the annual British Fleet World magazine, X-Trail for two consecutive years won the best four-wheel drive vehicle title.

X-TRAIL "--- the" X "represents a 4 × 4 vehicle challenge." TRAIL" is on behalf of the wheel track, the rough road and off-road terrain. These two elements combined, “X-TRAIL” representative novel 4 × 4 car. “novelty” of the whole pattern is that ALL MODE four-wheel drive system, which is controlled by computer, in the city, rain and snow poor road conditions, and the like under extreme circumstances can be chosen 2WD, Auto and 4WD lock mode, etc., methods of operation is relatively simple. it sounds good, but there is a deficiencies, which is that a real-time four-wheel drive off-road system without preparing low gear. Although reducing costs in the fuel economy, but without independent suspension and afterburner box design, It has essentially different with the traditional hardcore four-wheel drive, that is, in a real bad road conditions, disadvantages will emerge.

Trail's dashboard design is personalized. On the whole panel, it is relatively far from the sight of the driver, you must move your head a little to see it clearly. It might be a "ingenious design " to prevent drivers maintaining a single position. X-Trail performance is satisfactory. X-Trail has more advanced technology and equipment, such as advanced uphill start assist system, Hill Descent Control system, B-LSD and instantaneous yaw control system, vehicle dynamic equilibrium system (VDC). With intelligent all-wheel-drive system that matches the pattern is the world's leading Nissan Xtronic-CVT continuously variable transmission. Good operating smoothness and fuel economy; gearbox oil maintenance-free life, low maintenance costs.

X-Trail adapts a new chassis and suspension system, rear suspension with advanced multi-link independent structure, comparing to the link pillar structure of the first generation model, handling has been significantly improved; ground clearance is up to 200 mm or more, not fully take into account the urban and rural roads, and also offers excellent off-road capability. The suspension can be effectively filtered out bumps. However, during high-speed cornering, body appears tilt inevitably.

Nissan X-Trail also has a unique "ZONEBODY" regional body structure; the body structure will be divided into the whole body energy absorption and safe areas. The impact of the damage can be minimized, providing strong security for the occupants.