The most common form of four-wheel drive can be divided into three categories: four-wheel drive , timely four-wheel drive , AWD . Four-wheel drive
four-wheel drive (PART-TIME 4WD) mdash; four-wheel drive system for a driver to manually select between two drive and four-wheel drive, according to road conditions by the driver to change two-wheel drive or four-wheel drive mode by turning on or off the splitter, the most common of which is the four-wheel drive sport utility vehicle or SUV driving mode.
four-wheel drive by the operation of the splitter to achieve a four-wheel drive with two drive switching. Its advantage is simple structure, high stability, strong and durable, but the disadvantage is that the owners manual operation, and some complex structure, not just a step, but also need to stop operating, so that not only operate more trouble, but due to bad road conditions can not respond quickly, often miss the best time turning around; and second, because there is no central differential four-wheel drive, four-wheel drive system can not be used on a hard surface (paved road), you can not turn smoothly, especially in the corners .
In general, the vehicle is in four-wheel drive state is not the time, under normal driving conditions, is used in two-wheel drive, when required by the bad road, the driver can be driven by two points lever switched to four-wheel drive, four wheels are provided so that the driving force, thereby improving the performance of the vehicle through.
“Jeep Wrangler transfer case lever”
Operation: [123 ] vehicle specifically designed with a transfer means, transfer case some lever, some electronic buttons or knobs.
“Great Wall Hover transfer case control button”
on behalf of models: [ 123] JEEP Wrangler, such as the Great Wall Hover. timely AWD
timely four-wheel drive (Real-Time) mdash; mdash; simply be understood literally, it refers only appropriateWhen will the four-wheel drive, while in other cases still drive two-wheel drive system. Full-time four-wheel drive comes this name is different from the need to manually switch the two drive and four-wheel drive four-wheel drive, as well as all the conditions are four-wheel drive.
compared to full-time four-wheel drive, four-wheel drive timely structure is much simpler, which not only can also reduce costs, but also help to reduce vehicle weight. Due to the special structure timely four-wheel drive, which is more suitable for front-transverse engine platform models equipped with the precursor, which makes many based on this platform to build an SUV or four-wheel drive sedan equipped with four-wheel drive system is possible.
precursor platform relative to the rear-wheel drive platform itself has many advantages, such as more conducive to expand the interior space, higher transmission efficiency, quieter drive system and so on. These advantages for small SUV, especially the smaller engine displacement SUV, is particularly important.
Of course, the disadvantage still exists timely four-wheel drive and four-wheel drive when the vast majority of timely transmission power front axle, will be subject to defects in the structure itself, it can not be more than 50 percentage of power transmitted to the rear axle, which makes it the active safety control, no adjustment range four-wheel drive so much; at the same time four-wheel drive compared to that in dealing with bad roads, the physical structure of the four-wheel drive low limit.
Operation:
Most are designed to separate the car buttons, printed ldquo; LOCKrdquo; words, but also some automatic four-wheel drive state inductive Unicom, car no button.
on behalf of models:
X-Trail, RAV4, CRV, Koleos and so on.
AWD
mdash full-time all-wheel drive; mdash; Acronym AWD (All Wheel Drive shorthand). Specific meaning is: car traveling at any time, all the wheels are independent movement.
Full-time all-wheel drive vehicle will have more excellent than the safe driving two drive-based (2WD), in particular if theLimit or intense traffic while driving. In theory, AWD will have better traction than 2WD, driving the car is based on its continued smooth traction, stability and traction is mainly determined by the method of driving the car, the distribution of engine power output by the transmission system to the four tires and assigned to the two tires do the comparison, the result of AWD is controllable by and stability will be enhanced, i.e., whether the vehicle is traveling (on wetlands, rugged mountain road, curved road) pavement and what weather which time; the driver can better control every swath action to ensure the safety of the driver and passengers.
and while driving, full-time all-wheel drive steering style is also very characteristic, the most obvious is that it will turn more than two drive-neutral, generally before it can be better to avoid turning the different drive and rear-drive oversteer, which is one of the characteristics of driving safety and stability.
It is because of the presence of AWD, in order to provide a car ldquo; active safety, active driving rdquo; opportunities. Currently this technology should have been a lot of manufacturers, which contains the familiar Audi quattro, Volkswagen 4MOTION, Mercedes-Benz 4MATIC, Acura SH-AWD etc. hellip; hellip;
Operation:
direct driving.
on behalf of models:
Audi Q7, BMW X5, Mercedes-Benz GL, Acura MDX and so on.
