Subaru Forester 2002 test drive - 2005 SUV
Subaru Forester and Suzuki Liana: Two in one
Now would be all -wheel drive, - the drivers think sadly, stuck in the next snowdrift, “then I would instantly leave.” The business is all: the gazanil was stronger, and got out! Yes, indeed, the all -wheel drive transmission in such situations is always more profitable: it is easier to get out of snow -covered traps, you feel more confidently on the impassability, and in other modes of movement, the all -wheel drive car behaves more stable. True, all -wheel drive is very different, and buying a car with a 4x4 nameplate is not a panacea at all ...Full -wheel drive: Design features
Recently, the reader called us in the editor - I was interested in which SUV is better for him to buy for operation in the winter. He called a dozen models - both new and used - but not one of them, as it turned out, is suitable for him. Why? Yes, because our reader was going to drive in such a car in winter, it means that he needs a permanent all -wheel drive, and all the models he called had a connected all -wheel drive, which manufacturers themselves recommend using only in special cases. Reasoning that other readers who choose a new or used car can get confused in the same types of all -wheel drive transmission, we decided to tell about all the main types of transmission and clearly show how different models with 4x4 nameplate may differ.
The most simple and at the same time the most reliable, inexpensive and indestructible are transmissions such as Part Time, where the main drive is the back, and the front -wheel drive is connected by the driver only in case of emergency. This transmission is mainly equipped with inexpensive SUVs and pickups, although sometimes it is found even on relatively expensive American models. The peculiarity of such an all -wheel drive transmission is the absence of an interdicing differential, as a result of which the 4x4 mode cannot be used on dry coating. That is, you can constantly drive only on the rear drive, and the front axle can be connected (this is indicated in the instructions) only on slippery coating, when the probability of slipping of the wheels of one of the axes appears. Otherwise - accelerated wear of transmission, clutch and tires. But at the same time, the absence of an interdessual differential makes cars with the Part Time transmission with good passes - torque is distributed between the axes in a ratio of 50/50, which allows you to confidently feel in snow and a blurry primer, and on a plowed field.
The Full Time system, which has an interdose differential and allowing the car in all -wheel drive and on any coating, was the logical development of the Part Time system. Full Time transmission can be of two types - either with a constant all -wheel drive or with the connected. In both cases, the inter -sextile differential is equipped with forced locking, which is activated by the driver if necessary - this increases the passage of the car on the roads. With a blocked differential, the Full Time transmission becomes a similar Part Time transmission - in this mode, the car can also be operated only on slippery coating. But due to the fact that all the main time of the Intersose differential is free, that is, it is not blocked, the advantages of all-wheel drive can always be used, without any additional manipulations with governing bodies. And when the blocking turns on, then such a car is not inferior to those models that are equipped with Part Time transmission.
Differential blocking can be carried out either automatically or forcibly, at the command of the driver. The first type of differentials is called self -locking - the driver does not even know whether he is blocked or not - automation decides everything for him. That is, your business is just to put pressure on the gas and not think about any locks and redistribution of torque there. Convenient, and most importantly - quickly and imperceptibly. That is why self -locking differentials have become widespread on those types of all -wheel drive cars for which off -road abilities are not priority - in cars, SUVs and minivans.
The forced blocking of the differential has gained greater distribution on these SUVs, which requires great reliability and the possibility of transmitting a huge torque. In addition, compulsory is also compelled in that after its activation, the transmission of torque is carried out in only one proportion - 50/50, and this ratio can only be changed by turning off the lock. In self -locking differentials, the process of distribution of torque along the axes is extremely unstable: now it works in a ratio of 50/50, and in the next second it can throw 70%front wheels, and only 30. or vice versa - depending on which axis is which axis It is constantly driven, and which is connected.
Another feature of self -locking differentials - for their activation you need to slip the wheels of one of the axes. Then the automation recognizes slipping and connects the second axis, and after overcoming the obstacle, it will unnecessarily turn it off, leaving the car with front -wheel drive. All this is good somewhere on the ice or on a slightly soaked dirt road, but if you buried in a beach sand, then the automation will seem to you an extremely imperfect knot. Each time the car will start off, trying to get out of this trap, the front wheels will be the first to slip, digging the car even deeper, and only then, after that, the rear axle will be connected. Accordingly, the buildup will not help here - the front axis will simply dig finally, and the back will be connected with jerks, without bringing any real benefit. Forced blocking in this regard is more convenient: having blocked the differential, you have a constant 50% torque on each of the axes. You can start, you can rock the stuck car - both axes will work. And there will be several times more chances to leave in this case.
Additional off -road help may be forced blocking of inter -coil differentials - the rear, and sometimes the front. If the car can still be stopped with a blocked central, interdessual differential by hanging two wheels diagonally - the front right/rear left or vice versa. It is necessary to hang out one of the wheels of each axis, then the whole torque will go into a useless slip. This is the peculiarity of ordinary, free differentials - the power is transmitted to that wheel that is less loaded. That is why the diagonal hanging is considered the scourge of most SUVs: by hanging the wheels diagonally, you immobilize the car - the wheels spin helplessly, and the car is not from the place.
But if the SUV is equipped with a locking of inter -long differential, then the diagonal hanging for him is no longer scary. You drive up to the obstacle, hang the wheels diagonally - the car stops. But you block the rear differential, and now the torque in equal shares is distributed not only between the front and rear axle, but also between the rear wheels - in the same ratio, 50/50. Thus, to plant a car, you already need to bury at least three wheels - both rear and one of the front, through which the torque will go away that was fed to the front axle. And if there is also the anterior inter -long lock? Then it will be possible to stop the car only by a vertical obstacle: when blocking all three differentials - the center and both inter -cross - the torque does not go away, but is absolutely used to rotate the wheels with the same speed. True, the anterior inter -normal blocking is only on expensive professional SUVs, and on civilian models it is installed in exceptional cases.
Interdaemo -long blocking, in particular the rear interventor differential, is also forced or automatic. Forced is used in the same professional SUVs, but a self -locking differential in the rear axle is found in many SUVs and even in some cars. The principle of action - as in the case of an inter -shower differential - everything happens softly and imperceptibly, without the participation of the driver. As in the case described above, automatic inter -normal locking is most relevant in ordinary traffic modes, in the snow or blurry soil, but it helps little with serious ambush.
4wd or Symmetric4?
Today we have a slightly unusual test - two cars related to different price groups and completely different classes are presented to your attention. One is a representative of a parquet tribe, having a small admixture of a passenger station wagon, with a mandatory subclass all -wheel drive, and the other is an ordinary passenger microven, equipped with all -wheel drive, and recently proposed with a sedan type. Machines, in fact, have nothing in common - they are aimed at different consumer groups, have different consumer properties and generally do not intersect in anything. The only thing that they have in common is the presence of an all -wheel drive transmission that makes cars an order of magnitude more functional and more universal. And the rest - everything is like everyone else ...
Suzuki Liana, which has a front -wheel drive in the database and is equipped with a 4x4 transmission only by order, the all -wheel drive transmission was created according to the simplest class of the scheme. The main drive axis is the front, and the rear wheels are connected automatically in the case of the front slipping. There is no center differential - he plays its role, and at the same time knows the process of connecting a multi -disc clowing, which has two operating positions - ON. And off., And does not affect the distribution of torque through the axes. More precisely, there is no distribution as such in this case at all: the front axle takes everything for itself, and the rear, if necessary, can only get exactly the same portion of power, but nothing more.
The scheme of the all-wheel drive transmission Subaru Fores-ter (in the pictures-modification of the Turbo CO 177-Cyle motor) is completely different. Like all other representatives of this brand, a forester (as Forester translates into Russian) has a constant all -wheel drive - for all four wheels. There is an interdosseous differential supplemented by Wylskyoft, which can both block the center differential and help him distribute the torque along the axes. The usual ratio is 50/50, but in the case of slipping of one of the axes, the torque can swim in one or the other (on the front or rear axle), but only within 7%. That is, if you quickly drive along the snow and the front axis begins to demolish, it skips, the torque will slightly move to the rear axle, the percentage ratio will be 43/57. In the case when the rear axle is slipping, the additional power can be transmitted to the front wheels in the same way. In addition, Subaru Forester, as a more multifunctional machine, has a self -locking rear inter -long differential. And versions with an unmistered engine also have a decreasing gear - a real -sized shift from arsenal, despite the fact that a forester with an atmospheric engine is cheaper.
Advantages and disadvantages
Subaru all -wheel drive transmission is a knot that appeared as a result of natural selection - painstaking long -term work. This scheme used by the Japanese manufacturer is one of the most perfect in the world today, and thanks to it, Subaru has repeatedly won the rally championships. There are no shortcomings as such at all: Symmetric4 practically does not require excess fuel, does not give extraneous noise and vibrations, and also does not affect the dynamics of overclocking. One could also note the small weight of such a transmission. The front -wheel drive Subaru Impreza has an equipped mass of 1105 kilograms, and the all -wheel drive version weighs 60 kg more. The only one is Viskoft, which is the basis of such a full -wheel drive transmission, is quite expensive.
Suzuki Liana 4wd such a drawback as a high price is completely deprived of - this is the cheapest all -wheel drive car of this class, especially when it comes to minivans. Here, in the monotive version, you can still argue about the cost of Liana - there are many classmates with the same advantages, but as for the 4WD version, there can be no complaints. The all -wheel drive transmission Suzuki Liana is one of the most affordable in the market - for the right to have four leading wheels, you need to pay extra about $ 1,000. True, as we have already explained above, all four wheels leading can only be for a short time, and the front wheels play all the main time. Another very good feature of such a transmission is its unpretentiousness. In terms of maintenance cost, the all -wheel drive liana is not very different from the front -wheel drive, but even if the coupling someday refuses, you can not pay attention to this - you will go further, as on an ordinary front -wheel drive model.
Features of behavior and management
Both all -wheel drive cars, of course, are much more stable and dynamic on slippery and wet coating. You can fearlessly go into the turn sprinkled with snow, without fear of the skidding or demolition of the car, turn on the side of the road, not afraid to get stuck, etc. In the end, the advantages of an all -wheel drive transmission can be safely used on light impassability: on the beach, on dirt roads, on snow -covered parking. The main thing is not to play, not to forget where the lung ends and the heavy impassion begins, which is contraindicated in passenger cars, as well as the SUVs.
We tried cars in different modes, but since the test took place on different days, it turned out that Suzuki drove through wet asphalt and soil, and Subaru - along the snow and ice. But it doesn’t matter: last year we traveled on ice on the all -wheel drive Suzuki Baleno, on the platform of which Liana was created, so we have something to tell about the features of the behavior of such a transmission. But let's start with Subaru - it is more perfect and more powerful and more expensive. And - more interesting. After all, the basis of the forester is the legendary Impreza, the multiple winner of the rally, so the controllability of this unpretentious in appearance of the car turned out to be very gambling. Sliding, demolitions, drifts, slipping of all leading wheels - all this for Subaru is just as natural as for BMW M5 extreme starts from a place. And you need to pay tribute to this car - everything that you do not offer, it does just great. And any driver can cope with this turbocharged monster - the behavior of a foreman is extremely stable. Wyescoft is very serious about the distribution of torque of the moment, and in an hour and a half we have never had claims to her work. First, a small demolition of the front axle, then, if you carefully work out with gas and the steering wheel - a smooth entry of the rear axle, which can be controlled as a long time. If you just put pressure on the gas, then the car stubbornly crawls out of the trajectory, instantly returning back when the speed is reduced.
Suzuki Liana 4WD behaves about the same way: stable and reliably, delighting the smoothness of the course and the noiselessness of the work of all -wheel drive transmission. The all -wheel drive is turned on unnoticed, although if you take a couple of provocative actions, then the coupling will give itself out - a sharp start with a gas pedal in the floor and a clutch throw is accompanied by a sensitive blow to the transmission. This means that the coupling, slightly missing the moment of the beginning of the slip, turned on too sharply. Otherwise, the transmission is as trouble -free as on Subaru: no noise or vibration. True, if you go with all the money, then Liana with all -wheel drive begins to lose Subaru in almost all parameters. We do not take the calculation of accelerating dynamics, because their motors and transmission are completely different, but in general, Forester seems much more prepared and suitable for active driving on slippery coating. Having gotten off, you can ride this car as quickly as your instinct of self -preservation allows, and at the same time, special driving skills or rich rally experience will not be needed. Subaru Forester Turbo - Feel Tommy Myakinen! At the same time, the car has a relatively low price and an excellent turbo engine that makes the forester the fastest car in the classroom.
Suzuki Liana 4WD sedan is simpler in this regard: it is cheaper and not so well brought up in terms of controllability. This car is easier to tear into a skid, which can sometimes turn into uncontrolled, its all -wheel drive is connected a little longer and a little sharper, although it can be noticed only after a trip on such a reference car in this respect as Subaru. In general, Liana is a great option for those who are looking for an unpretentious, reliable, but inexpensive all -wheel drive car, without much complaints about the taxiways. You can say something like stability and reliability about him - our motto.
Text: Pavel Kozlovsky
A source: Autogazet / N 40 (432) dated 04.11.03
