When it comes to a crossover (a fashionable topic!), They certainly say that it must be not only universal and with a large (against the background of conventional cars) ground clearance, but also all-wheel drive. Even if the car is the most urban, and its owner never drives off the asphalt. Mono-drive versions are usually supplied only in the most inexpensive trim levels, and they are rarely kept in press parks. Maybe in vain? After all, if we discard the indisputable "pros" of the four driving wheels - cross-country ability (mainly on loose snow) and acceleration capabilities (under the same conditions), what else can be recorded as advantages? Moreover, perhaps on asphalt, the difference in mass and friction loss will make it possible to drive more economically? Maybe safer?

INTERESTING MATH

We took "Mazda CX-5" and "Renault-Duster", the hottest new items in the class. The all-wheel drive "Duster" even has a different rear suspension than its mono-drive counterpart - independent. Gearboxes for cars with a 2 liter engine are also tied to the number of driving wheels: automatic (and only that) - in the 4 × 2 version, while the 4 × 4 comes exclusively with six-speed mechanics. In Mazda CX-5, on the other hand, the type of drive has almost no effect on everything else. Even up to the equipment level - thanks to the Touring and Sport packages. The biggest differences are in tires and wheels. The 4 × 4 car is shod with 19-inch tires, the 4 × 2 modification is content with 17-inch tires.

We start measuring. Having driven the machines onto the scales, we find: four-wheel drive adds 70 kg to "Duster", and "Mazda" - more than a hundred. Although against the background of a total curb weight of 1400-1500 kg, this is a trifle. The difference in geometric cross-country ability is not great either, the front-wheel drive "Duster" has the latter even a little better.

Of the two Renault, the four-wheel drive accelerates faster, but this is mainly the merit of the mechanical box. The situation with Mazda is more interesting. The monodrive is more energetic in acceleration, which is felt even without the measuring equipment. Have front wheel drive only a small loss in maximum speed, but it is due to the selection gear ratios and big wheels 4 × 4 versions. Both cars hit top speed in fourth gear, but the 4x2 on 17-inch tires ran into the rev limiter earlier, unwilling to accelerate at the next, fifth speed.

By the way, the braking distance for both purely front-wheel drive cars turned out to be noticeably shorter.

FEELING THE DIFFERENCE

Well, how can we not recall the stereotypes regarding handling! On the changeover (imitation of avoiding an obstacle) it turns out that the Duster 2WD is faster and, most importantly, easier to control. He, unlike 4 × 4, does not at all seek to perform a maneuver abruptly. On the contrary: at first, the mono drive surprises with large rolls and too calm reactions to steering. All-wheel drive with its more active - independent rear suspension behaves assertively, and at times even furiously, as if urging the driver to respond. Such a car drives very confidently, especially considering the lack of a stabilization system. However, it is easy to make a mistake on it, and in the limit, a skid of the rear axle will force you to slip out of the corridor. "Renault" with front-wheel drive requires from the heart to turn the steering wheel in the fight against delays and understeer, but, unlike its brother, it goes into sliding softer.

Both "Mazda" - with a sensitive stabilization system, intervening in the management process quite early. But front-wheel drive turns out to be clearer again. So here, too, the speed advantage of the rearrangement is behind the front-wheel drive and 17-inch wheels.

Roads common use helped to finally prioritize. They showed better comfort mono-drive "Mazda" and its more correct cornering behavior. The all-wheel drive on 19-inch tires does not like irregularities at all: there is vertical buildup and even slight yaw. This is not critical, but how much more comfortable and simple a front-wheel drive car is. Moreover, such a crossover obeys the gas pedal much better. No thoughtfulness, languid pauses, even when the machine goes to higher gears. The 4 × 4 version often suffers from failures, especially when hard pressing to the accelerator.

And what about "duster"? Here, the front-wheel drive car was also more comfortable. And even more noticeably than in the case of Mazda. Both Renault cars are excellently struggling with the unevenness of the roadway, this family dignity cannot be taken away from them. But if the all-wheel drive Renault still makes you feel the depth and size of the potholes, sometimes quite sharply, then under the wheels front wheel drive car most of them seem to dissolve, causing only slight body wiggle. The most interesting thing is that the wheels on the "Duster" are the same, the differences are rooted in the suspensions.

FACTS AND ARGUMENTS

So, is all-wheel drive on the pavement an unnecessary appendage? It is not necessary to draw unambiguous conclusions. It's about something else: what to put at the fore when choosing a car? In Russia, crossovers are legally popular: universal body, higher ground clearance and better suspension capabilities. In a word, their relevance is not only a tribute to fashion. That is why it is so important to separate “necessary” from “not so”. Our test is an attempt to figure it out. It is especially worth thinking about those who, changing regular car on the "SUV", yet does not plan to change the asphalt.

Don't forget about increased consumption fuel in all-wheel drive versions, all other things being equal. In addition, in addition to all-wheel drive, they often impose expensive configurations: let's remember at least 19-inch tires "Mazda CX-5". I suspect that this crossover was carried out on tires of a much more modest dimension. "But it's beautiful!" - marketers will object. And in their own way they will be right.

The front-wheel drive "Duster" demonstrates excellent ground clearance, excellent smoothness, reliable behavior on the road, and its trunk is as much as 70 liters larger than that of its all-wheel drive counterpart. Therefore, in search of the optimum, it is not at all necessary to focus on the number of driving axes, sometimes there are more important arguments.

HOW THE COUPLING WORKS (Gennady Emelkin)

Structurally, the operation schemes of the connected all-wheel drive Renault Duster and Mazda CX-5 are similar. Both vehicles have an electronic clutch located in the rear axle gearbox housing. She, guided by the information on the difference in rotation speeds of the front (main leading) and rear wheels coming through the sensors of the anti-lock braking system to the control unit, if necessary, is blocked by connecting the second axle. The clutch control algorithm is rather complex and depends on a number of external factors.

The diagram opens in full size by mouse click.

The scheme of work of the all-wheel drive "Mazda CX-5" is as follows. With uniform movement, when the wheel speeds are the same, the torque is applied to the clutch housing (4) ... Discs (5) the control clutches are open. Slave (1) and presenter (7) the discs are stationary relative to each other and rotate together with the driven shaft of the clutch (9) connected to the main drive shaft of the rear wheels. Torque on rear wheels not getting through.

As soon as the wheels of the front axle begin to slip (angular difference 15-20 degrees), the four-wheel drive control unit sends a signal to the solenoid coil (2) ... Magnetic field anchor (8) is attracted to it and compresses the control clutch discs (5) that connect the drive disc to the clutch housing (6) ... Due to the difference in their speeds, the drive disk turns, the balls (3) move along the inclined guide groove and shift the driven disc, which compresses the main clutch discs - the clutch is engaged.

To disengage the clutch, the control unit removes the signal from the coil, the control clutch discs open, the drive disc turns, the balls return to their original position - the main clutch discs open. This will happen not only with a steady steady motion, but also when the anti-lock braking system and the dynamic stabilization system are triggered.

Protection is provided to protect the clutch from damage in harsh conditions. When the oil in the gearbox heats up to 100 degrees, the control unit turns off the clutch and does not turn it on until the temperature drops to 60 degrees.

16.01.15

How does Renault Duster all-wheel drive work?

general information

In general, the drive system of this car model is quite simple and it is not difficult to understand it even for a non-professional. The distribution of torque between the wheels is carried out from the gearbox. On the outer ends of the shafts, constant velocity joints are installed, which receive equal angular velocity, and on the inner ends there are tripods. This mechanism of operation does not represent anything new in terms of development; the scheme is borrowed from the famous Nissan Quashkai.

Modes of operation

The most basic mode is called 2WD, which includes the operation of only the front wheels and is recommended for driving on a high-quality and dry road surface... This mode provides an economical ride in terms of fuel consumption and a comfortable travel speed.

Automatic mode determines the best grip on the ground. It is mainly used on highways and city roads. In unfavorable weather conditions, for example, during rain, the clutch independently determines at what moment it is necessary to connect the rear wheel drive.

In a mode called LOCK, the clutch is locked and torque is supplied to the rear wheels, so the car becomes full drive and ready to overcome the off-road. However, this function is recommended for operation at reduced driving speeds of up to 80 kilometers per hour.

Outcome

Car owners Renault Duster must independently, depending on the situation, choose the optimal operating mode of the drive and remember that the most economical driving is obtained in 2WD mode, and in LOCK mode it is advisable not to be in the LOCK mode for too long, so as not to overheat the clutch, which can lead to a breakdown of the mechanism, especially since repair at the current price, Renault Duster 2014 can be quite expensive!

All entries

Renault Duster 4x4 immediately after entering the market, aroused great interest in Russian market... Enough interesting characteristics the crossover was immediately appreciated by thousands of Russians. Today we will analyze in detail the device of the complete Renault drive Duster and transmission modes.

The principle of operation of Renault Duster 4x4 is not new, something similar is used on other small crossovers. For example, the all-wheel drive transmission of Nissan Kashkaya and Dzhuka works in the same way. In the photo at the beginning of the article, a diagram of the work of the Renault Duster all-wheel drive.

The Duster 4x4 gearbox is made in a single housing with an additional transfer gearbox. When the front wheels rotate, the shank of the dispensing unit constantly rotates, to which it is attached cardan shaft... And already the propeller shaft transfers the torque to the rear gearbox. But in front of the rear gearbox there is an electromagnetic clutch, the task of which is either to transmit the torque further, or to allow the cardan to rotate idle. It is this clutch that is the main element of the connected rear-wheel drive, without which there would be no 4x4 transmission on the Duster at all. How does this drivetrain look from the back, under the underside of the crossover? See the photo below.

The work of the entire four-wheel drive can be done from the interior of the crossover using a small washer, which just blocks or unlocks the electromagnetic clutch. Thereby transforming the mono-drive compact crossover into an all-wheel drive SUV. There are three operating modes in total.

The first mode of operation 2WD- the front wheels and the universal joint rotate, but the electromagnetic clutch does not transmit torque to the rear gearbox.

All-wheel drive “Lock” mode- the electromagnetic clutch is blocked and the torque goes to the rear gearbox, then to the rear wheels.

Automatic mode "Auto"- In this mode, when the front wheels slip, for example, on ice or other slippery surfaces, the electromagnetic clutch turns on by itself and forces the rear wheels to rotate as well.

It should be noted that it is impossible to constantly drive in the “Lock” mode, as this will lead to overheating of the electromagnetic clutch and its breakdown. Naturally, in all-wheel drive mode, fuel consumption for the Duster 4x4 increases, especially on the off-road.

We decided to evaluate the capabilities of front-wheel drive using the example of Renault Duster with a 1.6-liter engine. All-wheel drive versions are equipped with a 6-speed manual with a "short" first stage, which plays the role of a lowering. When you need to make your way over stones and swamps to a forest lake or river, then you cannot do without the first gear with a gear ratio of 4.45.

Photo: Renault

If you spin the Duster motor under the red zone and bring it to the maximum power mode, then the crossover speed at the first stage will not exceed 15 km / h. This is convenient, since you can go through the ford and mud baths without fear of a lack of traction.

In addition, the all-wheel drive Duster, thanks to the off-road gear ratio, can take off from standstill to Idling and even climb large boulders. The engine settings allow you to almost not touch the gas pedal if you need to carefully crawl along the blurred mountain roads.

Photo: Renault

However, in the city, the first transmission of the six-speed is not interesting. She only pushes the car forward and immediately has to switch to the second. Therefore, in order to save time, many drivers start immediately at the second stage, considering it to be quite suitable for this. It's not entirely correct to think so, because a gear ratio of 2.59 is not always suitable for a full start. You have to keep the clutch semi-open longer, which is why its increased wear is observed. Therefore, for residents of large cities for whom off-road problems are not obvious, front-wheel drive and 5-speed transmission seem to be preferable.

Photo: Renault

The versatile workaholic

In the front-wheel drive version, the Duster's first gear works like the vast majority of cars with mechanical box... Its gear ratio is smaller (3.73), which makes the car accelerate faster. Slightly pushed the pedal, and the crossover has already rushed forward. At the peak of thrust of a 115-horsepower 1.6-liter engine, such a Duster in first gear travels at a speed of 40-45 km / h. Therefore, the five-step is more convenient in the city, but it passes on the off-road.

Photo: Renault

As a city car, the front-wheel drive Duster is incredibly good. He responds more interestingly to spurring. Because of the large opening of the door, you do not sit in the driver's seat, but enter as if you were entering your personal account. The door swings wide, which is why you are not afraid to hit the roof with your forehead or eye. At the same time, the "gate" is very light.

Back access is also simplified. If you put your child in Baby chair, then you do not have to reach and bend like a tower crane. Everything turns out easily and imperceptibly.

Trials for front-wheel drive begin in late winter, when February and March snowfalls finally defeat utilities and yards turn into impassable snowdrifts. It is difficult to get to the house. But the front-wheel-drive Duster has high ground clearance. And these problems are not as terrible for the crossover as for the vast majority of "puzoterok".

Photo: Renault

Its center of gravity is shifted slightly forward. Rear axle no, like cardan shaft causing the car to lean more on the front wheels. Therefore, the hold is not bad. On the steep slopes Duster crawls much better hatchbacks and sedans on the related B0 platform.

But he cannot ram the snowdrifts like the Defender. As soon as the front end is buried in the virgin snow, slippage begins.

Photo: Renault

But in the summer, the front-wheel drive Duster will crawl through almost the same place as the all-wheel drive. Dirt road with puddles or gravel with pits he does not care. The difference in cross-country ability is noticeable only on mountain slopes, where the drive wheels are hung out when driving. Even when traveling on a fishing trip or to a remote village, you can only do with front-wheel drive.

In general, the possibilities of all-wheel drive are mythologized in our country. Comes to the ridiculous. Sometimes you specifically look for difficult places that only "real off-road vehicles" can do. You climb along the paths somewhere to the "holy spring", indulging your conceit that no other car will pass you here except a tank. And at the finish line you find front-wheel "Lada" and the old Togliatti "classics".

Difficulties of the off-season

However, in spring or autumn, there are still places where all-wheel drive is indispensable. For example, you need to drive a couple of kilometers to the dacha. And after the snow melted, the road was killed by a truck, which deepened the track, and it became impassable for cars. All climb into a detour on the virgin land. Soggy loams overgrown with grass easily wind up on the wheels, and the car gets stuck. Of course, the electronics of the front-wheel-drive Duster helps to get out somehow. But you can't argue with the laws of physics, and if there is no hook, then the crossover sinks out of the blue.

Photo: Renault

The all-wheel-drive Duster drives much better in such places. Blocked the clutch 50/50. The thrust is sent to rear axle, and even with three skidding wheels you can crawl out of the trap.

All in all, four-wheel drive is a big dilemma. The need for it among ordinary motorists arises only a couple of times during the entire operation of the car. And the all-wheel drive Duster costs almost 120 thousand more. A front-wheel drive vehicle with a 1.6-liter engine will also cope with many urban problems.

However, if hobbies and hobbies are drawn to adventures associated with frequent visits to the hinterland, then the overpayment for four-wheel drive seems reasonable. You cannot save here. Fishermen, mushroom pickers and hunters will not deny themselves the pleasure of blocking the clutch and crawling through the puddles along the axis with depth. The all-wheel drive Duster has phenomenal cross-country ability even with a 1.6-liter unit under the hood.

Specifications Renault Duster

	Renault Duster 1.6 2WD MT5	Renault 1.6 4WD MT6
Dimensions (length / width / height), mm	4315/ 1822 / 1625	4315/ 1822 / 1625
Wheelbase, mm
Curb weight, kg
Trunk volume, l
Body type	Station wagon	Station wagon
Number of doors / seats
Engine	4-cylinder, in-line	4-cylinder, in-line
Working volume, cm³
Maximum power, hp with. / rpm
Max. torque, Nm / rpm
Transmission	5-st. mechanical	6-st. mechanical
	Front
Ground clearance(mm)
Volume fuel tank, l
Acceleration to 100 km / h, s
Max. speed, km / h
Fuel consumption (mixed), l / 100 km
Test car price	From 689 000 rub	From 809,990 rub

With the entry of Renault Duster cars into the domestic market, it became very popular. This is due to the fact that for relatively low money, the consumer receives a high-quality crossover with all-wheel drive. For many car enthusiasts, the 4x4 function is a must, since they have to drive off-road quite often. This is especially true of farm and forest land. But, what is the principle of all-wheel drive on Renault Duster?

Enabling all-wheel drive

First, let's consider not the technical side of the issue, but the functional one. As the current automotive trend tends to reduce fuel consumption, cars are often installed on switches from four-wheel drive to conventional.

Renault Duster has not lost this useful functionality either. So, in the car there is a washer-switch, which allows you to turn on different modes... Let's consider the question in more detail:

1. Lock function. This is just four-wheel drive. It locks the distribution clutch and there is a forced load on all axles of the vehicle. When using the Lock mode, it is not recommended to drive faster than 70-80 km / h in order not to cause breakage of the lock-up clutch.
2. 2WD function. The name itself speaks for itself. This mode only engages front-wheel drive and is ideal for highway driving.
3. Electrofusion button in the "2WD" mode
4. Electrofusion button in the "AUTO" mode

Thus, it can be seen that both the control unit and the driver himself can choose which mode to drive.

The principle of all-wheel drive on Renault Duster

If we talk about the principle of operation of rear-wheel drive, it is necessary to understand some technical and design features Renault Duster. In the case of front-wheel drive, all the torques go through the CV joints to the front wheels. But how does the rear one work?

In this case, the vehicle is equipped with transfer case, which redirects torque to the rear wheels. The system was invented a long time ago, back in the distant 50s, but the principle has remained to this day, although these devices are being improved all the time.

Classic scheme of plug-in all-wheel drive

V rear gear Renault Duster has a clutch installed, and if it is blocked, the rear-wheel drive does not work. It can be turned on both forcibly by the driver and with the help of an ECU. Let's consider everything more simply and clearly: the engine supplies torque to the gearbox, and from there it goes to the junction box.

Through the propeller shaft, it enters the rear gearbox, in which there is a clutch regulator for engaging the rear drive. If it is on, then the four-wheel drive works, if it is off, then only the front one. The rear gearbox has its own oil, which requires replacement.

Let us remind you once again that it is not necessary to forcibly use the clutch-switch during long term because it can fail under power load. Therefore, the AUTO mode is considered the most optimal to use.

Where necessary, it is worthwhile to briefly turn on the manual mode, and when it becomes unnecessary, switch back to the AUTO mode.

The all-wheel drive operation was simple and straightforward. Of course, if the clutch fails, you will have to replace the entire assembly, which is expensive, so you should follow the rules for using the 4x4 mode.

Take a look interesting video on this topic: