Why do we continue to talk about car drives? Today we have a global topic, namely, what is better and what to choose, front-wheel drive or all-wheel drive for an SUV or crossover? As you and I know, it is not entirely honest, that is, it is not permanent and often does not have a hard differential lock, that is, you cannot manually lock it, it is engaged only after the front axle begins to slip. And now a completely fair question arises - “is it necessary or is the front axle enough for the eyes?” Everything is not clear here, let's figure it out...
Well, I won’t say in general that all-wheel drive is bad! Still, I think that quite the opposite, it’s even good! There are large and heavy cars where it works constantly, which greatly improves cross-country ability. There are also not very large cars, middle class “C”, sometimes “D”, where it is also permanent or hard-wired (which improves cross-country ability and handling under certain conditions), but SUVs or crossovers are completely different. All-wheel drive in them, unfortunately, has now become the property of marketers and businessmen, that is, they are trying to prove to you that they are “digging” with four wheels, but in the end everything turns out completely wrong. In this article I will try to debunk all the myths, but for a better understanding you need to talk about each type, and I think it’s worth starting from the front.
As we already said, many “copies have been broken” about this topic, but there the principle of conversation is different; nevertheless, there is one driven axle either in front or behind, today the essence of the issue is different.
The front-wheel drive is very simple in structure, and it has now been practically brought to perfection, that is, it can run for a very, very long time without any breakdowns.
Device :
- Engine
- Attached to the engine is a gearbox with differential, often in the same housing
- From the box (differential) there are two axles with . There are two CV joints on each side (internal and external)
- These CV joints fit to the front wheels through special hubs.
Torque is transmitted from the engine - transmission - axles - wheels. This is how a front-wheel drive car is driven.
It is worth noting that there is not a lot of transmission fluids here, that’s all in the box itself, as a rule, the other connections are dry (well, or almost dry, after all, there is lubricant under the boots in the CV joints, but there is really a minuscule amount of it and it does not change). This tells us that we don’t have to monitor this design at all. Of course, I still advise you, because if they break, the hinge will soon fail, but believe me, for the next 70 - 80,000 km you don’t have to do this. If the manufacturer is serious, then the anthers can last 150 – 200,000 km.
The rear suspension in front-wheel drive does not carry any semantic load, that is, it is a banal “support for the wheels”, there is practically no weight, it is light here (either a beam or a “multi-link”). And what’s important is that the rear part requires virtually no maintenance, unless you change the brake pads.
Four-wheel drive
Even all-wheel drive connected through a viscous coupling has a much more complex structure (I’m already silent about permanent ones). There are more parts that spin (most of the time) at idle, there are now two axles rather than one, a driveshaft also appears, and the rear axle is no longer secondary.
Device :
- Engine
- A gearbox that can be combined with a front differential. However, the front differential can be moved separately
- Front axle with CV joints on the front wheels
- Center differential, it can also be in the same housing with the gearbox, but it can also be separately (it all depends on the design)
- Transfer case.
- Rear cardan for transmitting torque to the rear axle
- Viscous coupling or electro-coupling (hydromechanical) for automatic connection of the rear axle
- Rear axle. It can be made in a cast housing, from which two axle shafts come out to the rear wheels. But now, often from the rear differential there are also two axles with CV joints, similar to the front axle.
As you can see, the structure is much more complex! Two more differentials appear here, center and rear, there is also a transfer case, viscous couplings, etc. All this adds at least 100 kg to the car’s weight, and possibly more. There are also a lot of parts that “spin” in the oil and you really need to keep an eye on them. Some manufacturers recommend changing the transmission oil in them. If any seal leaks, the entire assembly may fail. I think everyone understands this, but again everyone thinks since I have all-wheel drive, then I’ll drive some kind of SUV or crossover, a RAV4 or the same Duster, I’ll just become an off-road conqueror - “what do I need a UAZ, I’m like a UAZ myself” ! BUT is this really so?
All-wheel drive via viscous coupling (electric coupling, hydromechanical coupling)
Well, now we’ve come to the most interesting thing: who is the all-wheel drive of such crossovers for, where can it be used? For many, this means that you can immediately go to the forest to pick mushrooms and berries, that you can overcome such off-road conditions, that, as they say, “at the door”! Guys, stop, all-wheel drive on crossovers and SUVs is very conditional, I would even say “urban”, it is not intended for serious off-road testing.
Why? It's just not designed for that. Often on many crossovers it is connected via a viscous coupling or electric coupling
- Viscous coupling , we have already talked about it (you can see it in detail). Transmits torque through a special fluid contained in the viscous coupling housing. When one axle begins to slip, the fluid quickly hardens, thereby locking the rear axle and engaging it. The disadvantages of such a drive are that it is almost impossible to turn it on yourself or lock the rear differential to work. ONLY AFTER SLIPPING. Therefore, the efficiency of such all-wheel drive is quite low.
- As it becomes clear, the work happens a little differently. There is no special liquid here, but there are electromagnets that close or open the disks when voltage is applied to them, thereby connecting or disabling the all-wheel drive. This clutch is dry, there is no oil in it, which is both good and bad. The good thing is that you don’t need to monitor seal leaks and change the fluid. The bad news is that this clutch overheats quickly. All-wheel drive is engaged after the front-wheel drive slips, usually after the second rotation of the front wheel. Some cars equipped with such a unit have forced locking, that is, you can physically lock the rear axle. It seems like this is the SOLUTION, the control is much better than that of a viscous coupling, BUT THERE IS A BIG FLY IN THE OIN. Such a drive overheats very quickly and turns off; if you can slip for a long time with a viscous coupling, then an electromagnetic clutch will turn off after 3 - 5 minutes of slipping. They also fail faster due to high temperatures; as experts say, they simply burn.
- Hydromechanical coupling. Very similar design to the electromagnetic version. However, here the discs are closed due to oil pressure. There is a pump inside that creates pressure to compress or expand them. Pumps can now also be electrically driven; previously they were mechanically driven.
Actually, such designs are used on a large number of crossovers or SUVs; it’s very, very difficult to find another one here.
Full or front?
As you can see, calling such all-wheel drives FULL-VALUE is mind boggling! What are they sharpened for? You know, I once talked with a “seasoned” mechanic about such automatic connections, and this is what he told me - “it will be expensive to get into even (average dirt) on such machines, they are simply not designed for this off-road, don’t think that you We bought a car with cross-country ability similar to our UAZ, THESE ARE DIFFERENT CLASSES! Especially if you have an automatic transmission, because it can also overheat quite quickly (with a manual transmission everything is a little better). These cars are designed to cope with a snow-covered yard in the city in winter, or with a couple of shallow puddles on the way to the dacha.”
You know, like a shovel in your trunk or a neighbor passenger - what do I mean? On a front-wheel drive car, you will need to clear the track in front a little (using a shovel), or ask a fellow passenger to give you a little push. But such a plug-in all-wheel drive car can get out on its own. Fine? Of course yes! BUT is it worth overpaying for it?
If you look at the front and full versions, you should think about where and how do you move? It is also worth considering that an all-wheel drive vehicle:
- Costs more.
- Options with all-wheel drive are at least “mid-range” and “top-end”, that is, you won’t find it in the “standard” version.
- The car weighs more
- More vibrations. Because more nodes are spinning.
- Maintenance costs more
- More rotating elements, which reduces the resource
- More fuel consumption
- Modest capabilities of this all-wheel drive car
Actually, if you are a 100% city dweller, snow is removed in cities, you go to the country where there are a few meters of dirt that are not very comfortable - THEN TAKE SUCH ALL-WHEEL DRIVE, AS I THINK IT IS AN OVERPAYMENT, AND IT IS NOT NEEDED!
Instructions
Information about the type of drive must be indicated in the documentation for your vehicle. Read them carefully and look for any mention of drive type. If documents are currently unavailable, use other methods.
Most vehicles with four-wheel drive have “4WD”, “AWD” (all wheel drive) or “4x4” badges on the tailgate or rear fender. Try to find them.
In all cars with all-wheel drive, there is always another lever in the cabin next to the gearshift knob. He is responsible for switching the transfer case. This lever has several positions. The most common:
- “N” – neutral position when none of the bridges is connected;
- “2H” – rear axle drive is engaged;
- “4L” – all-wheel drive with low range is activated;
- “4H” – all-wheel drive is on.
A similar lever is present even if the car is not equipped with permanent all-wheel drive. The positions of the four-wheel drive control knob can be as follows:
- “LL” – low speed;
- “H” – high speed;
- “HL” - high speed with the center differential lock on;
- “N” – neutral position.
If your car does not have these handles, it is quite easy to determine what type of drive it has, front or rear. Try to move away as quickly as possible. Then look at which wheels were spinning in place. If the rear ones, then they are the ones driving on this car, i.e. the car will be rear-wheel drive.
In addition, the way the car moves is also different. On a slippery road, the nose of a rear-wheel drive vehicle skids. This makes driving such cars dangerous in the winter. However, rear-wheel drive cars accelerate better, which is why almost all racing cars are rear-wheel drive.
Determining the type of drive is important if you often use CDs or DVDs. Without knowing which drive you have installed, you run the risk of buying discs that it simply won't read, and you'll end up wasting your money.
You will need
- - CD/DVD drive
Instructions
Determining the type of drive by the inscriptions on its front side. On absolutely every drive, the basic information about the device must be written on its front side. So, in addition to the manufacturer’s logo, on the drive you can see information such as the maximum rotation speed, as well as the supported type of disk. If the device has a DVD, it is designed to work with the corresponding disc format, but if it only has a CD icon, you will not be able to work with DVDs on this drive.
Determining the drive type by the sticker on the device. On the top surface of the drive you can see a sticker that will display absolutely all the information about the device. You can understand whether the drive can work with CDs or DVDs by reading the relevant information on the label. If it doesn't say anything about DVDs, this means that the device will not be able to work with such discs. To read all the information, you do not have to be a native speaker of the language in which it is presented - the mere presence of the inscription “DVD” will allow you to understand that the drive is designed to work with this format.
Determining the type of drive by its display in the system. In order to find out which drive is installed on your computer, open the “My Computer” section on your PC. If the drive supports the DVD format, it will be displayed as a “DVD drive”; if it does not support this format, then the device will be displayed as a “CD drive”.
Video on the topic
Sources:
- what drive do I have?
The type of drive on a car is the wheels that drive the car. On some vehicles, the drive type can only be determined from the technical documentation. But if it is lost, you can use our tips and determine the type of drive yourself.
Instructions
There are three types of drive: front drive, in which the front wheels are driven, rear drive with the rear drive wheels, and (permanent and switchable) in which all four wheels can be driven.
The easiest way to define it is all-wheel drive. Firstly, the tailgate may have 4*4, AWD (all wheel drive) or 4WD indicating all-wheel drive. Secondly,
Hello, dear blog readers website. In our conversation with you today, let's try to choose car drive and find out which drive is better: front, back or full? Drive car- this is one of its most important characteristics, so before you decide, which drive to choose, you need to figure out what types of car drives differ from each other.
Plan for choosing a car drive:
What kind of drive: front, rear or all-wheel drive?
Drive car determines to which wheels is the engine's thrust transmitted?. All modern passenger cars have four wheels - two front and two rear, while the engine power of the car can be transmitted either to all four wheels or to one pair of wheels - front or rear. How do they differ from each other? front, rear and all-wheel drive?
Which drive is safer? Which drive is the safest?
It is much easier to control; a front-wheel drive car is more difficult to skid, so as a first car it's better to choose a car with front wheel drive. On the other hand, skidding rear wheel drive car can be easily corrected by intuitively releasing the gas - I released the gas and the car returned to the trajectory. And on front wheel drive skidding means that the driver has crossed all permissible limits. Here's a small example.
Cause a skid front wheel drive car more difficult than in the rear, but also to get out of a skid on front wheel drive– you need much more skill. On rear wheel drive, skidding is the norm and it occurs all the time, and to eliminate it it is usually enough to simply release the gas pedal. It can be said that rear drive immediately shows the driver all the danger of a slippery road, and the front one hides it from the driver until the last moment. However, even for rear wheel drive There is a speed limit beyond which releasing the gas cannot stabilize the car. Look how a rear-wheel drive car can skid.
Concerning all-wheel drive, then still with him more difficult. All-wheel drive may behave poorly on slippery surfaces like front or like rear, depending on which wheel it is slippery under. Let's look at the example of the most popular model Chevrolet NIVA how a permanent all-wheel drive, not equipped with ESP system. This once again confirms that four-wheel drive only increases cross-country ability And improves acceleration dynamics, but not at all does not improve handling.
And in this video, at a speed of 150 km/h, an Audi car equipped Quattro permanent all-wheel drive, falls into an oil puddle and goes into a skid. Only the pilot’s wealth of experience and nerves of steel allow him to emerge from the water dry and unharmed.
For front wheel drive more typical high directional stability than the rear one. On a snowy or muddy road front-wheel drive walks like a steam locomotive on rails, while rear wheel drive You must operate the gas very carefully on a slippery road - the car may spin out.
And here four-wheel drive It handles snow porridge, as well as off-road conditions, even better than the front one, but if there is no center differential, then it is reluctant to turn. Be careful!
Allows you to accelerate faster, easily enters a skid, but also easily gets out of it, and all this together makes driving a rear-wheel drive car more interesting. On a slippery road rear drive It handles completely differently than the front one, but many drivers appreciate it for this. In general, if safety is not the last priority for you, and you want not only to drive a car, but to be able to drive it in any situation, then be sure to watch this video from Main road:
So, which drive is considered safer?? Unfortunately, this question cannot be answered unambiguously. Every type of car drive behaves differently, each has its own pros and cons, each type of drive it must be used skillfully without violating the laws of physics. But one thing is certain: if you need safe car, then it can have any type of drive, the main thing is that it must be turned on exchange rate stability system - ESP. This clever program is capable of braking each wheel individually, thus correcting many driver errors.
Which drive is the most passable?
Really, front wheel drive cross-country ability is slightly higher than that of the rear and there are at least two reasons for this. Firstly, driving wheels front wheel drive pinned to the ground by the weight of the engine, which reduces slipping. Secondly, driving wheels front-wheel drive, are the helmsmen, and this allows the driver to set the direction of traction.
If the drive wheels slip, the driver of a front- or all-wheel drive car can use the front wheels to pull the car out of the snow cap, while the rear wheels follow strictly behind the front ones. Rear-wheel drive behaves worse in such a situation - the rear begins to demolish; it is very difficult to control this process.
, on a slippery slope climbs more confidently than the rear one. The driving front wheels slip, but pull the car to the top, and rear drive, in such a situation, the car skids and tries to turn around. The king of slippery climbs is undoubtedly His Majesty four-wheel drive, which climbs an icy slope without slipping.
And yet, when driving on slippery roads in winter, you cannot rely only on all-wheel drive, because its capabilities are not limitless. With studded tires, you can climb a slippery winter slope with any drive, especially if the car is equipped anti-slip system ESP.
So, the most passable, of course, is all wheel drive. Rear-wheel drive is least suitable for off-road assault, but even with front-wheel drive it is better not to drive off hard surfaces.
Suitable for you if you do not plan to leave paved roads. If you are sometimes going to make risky forays into the fields, then you should at least take a car with front wheel drive, and for serious off-road excursions you will need a car equipped all-wheel drive.
On dry asphalt rear drive accelerates faster than the front one. When accelerating, the weight of the car is transferred to the rear axle, while the front wheels are unloaded, that's why front-wheel drive during acceleration allows for strong slipping. But the car accelerates the fastest with all-wheel drive Naturally, for this it must be equipped with a powerful engine.
So, if you need a car that accelerates faster than others, then you need to choose a car with rear, or better yet with all-wheel drive and as powerful a motor as possible.
Which drive is better? Front or rear wheel drive?
outperforms the rear one in terms of indicators such as fuel consumption. Average, front-wheel drive is more economical rear, and the difference can reach 7%. And here four-wheel drive, in terms of efficiency, takes an honorable third place - it the most gluttonous, largely because of this, most motorists choose front or rear drive.
In rear wheel drive cars, the front wheels do not have drive shafts, so the maximum steering angles on rear-wheel drive are greater, and turning radius – less, which is very useful in city conditions.
Front-wheel drive is cheaper to produce rear-wheel drive, so front-wheel drive cars are sold at more affordable prices. Lower price– this is the main advantage of front-wheel drive over rear-wheel drive and all-wheel drive. It is thanks to the low price that front-wheel drive has won the place of the most common of all types of drive: More front-wheel drive cars are being produced than with rear-wheel drive and all-wheel drive combined. The second reason for its high popularity front wheel drive is simplicity its use on a slippery road, its low demands on driver skill.
If you choose front or rear drive, then in most cases front-wheel drive is the best option. It is more accessible, more economical, simpler to design and less demanding on the pilot’s skill. – Your option if you already have decent experience behind you, and now you want not just to drive a car, but enjoy
from the very process of driving a car.
Which car drive is better? So, we need to summarize. If everything is greatly simplified, then the conclusion can be drawn as follows: the best type of drive is all-wheel drive , working in tandem with ESP stability control system . However, all-wheel drive more expensive to purchase and expensive to maintain , yes and consumes a lot of fuel . If you need something more economical , That Front-wheel drive would be the best option rear drive, which has the perfect combination of characteristics. well and You should choose only if you have experience and you need the car, first of all, to.
enjoy driving
- Advantages of front-wheel drive:
- Low price
- Reduced fuel consumption
- Cross-country ability is higher than that of rear-wheel drive
Holds course well on slippery roads
- Rear-wheel drive advantages:
- Accelerates faster than the front
Easier to get out of a skid
- Advantages of all-wheel drive:
- Cross-country ability is much higher
Accelerates even faster than rear-wheel drive
- Disadvantages of all-wheel drive:
- High fuel consumption
- High price
Expensive repairs and maintenance We have discussed the main types of drive, now let's see what they are.
types of all-wheel drive
Types of all-wheel drive In this version all four wheels are permanently connected to the engine
, each of them always clings to the road and pushes the car forward, and this in itself is a big plus (for example, on a slippery slope). However, permanent all-wheel drive really good only when it is equipped with stability control (), which brakes the desired wheel and prevents it from slipping if it hits a more slippery surface.
Disadvantage permanent all-wheel drive is high fuel consumption, and the advantage is greater reliability. Concerning cross-country ability, then it is possible to storm off-road spaces with permanent all-wheel drive, but only if its design includes locking central and center differentials.
Advantages of permanent all-wheel drive:
- Always Ready
- High reliability
Disadvantages of permanent all-wheel drive:
- Increased fuel consumption
Manually engaged all-wheel drive
This is the oldest and most inconvenient type of all-wheel drive, and here cross-country ability she probably has the tallest. Such a car, in normal condition, has rear drive, and the front wheels can be engaged manually, but this requires a stop. You cannot constantly drive with the front axle connected in such a car, as this creates loads on the transfer case and accelerates tire wear. Also, the disadvantage of this scheme can be considered quite high fuel consumption, regardless of whether all-wheel drive is on or off.
This type of all-wheel drive also has its own advantages. Firstly, such a drive is very good off-road, and secondly, he is also has very high reliability.
Advantages of manually connected all-wheel drive:
- High cross-country ability
Disadvantages of manually connected all-wheel drive:
- Inconvenience of engaging all-wheel drive
- High fuel consumption
Often various names are used interchangeably for the all-wheel drive of a car: 2×2, 4×4, 6×6, 8×8, 12×12, 24×24, 4WD, AWD, Four-wheel drive, etc. But in fact In fact, an AWD drive system should not be on the same level as an all-wheel drive system on all four wheels (4x4 or 4WD).
The point is that there are key differences between them. Perhaps you've never heard of the differences between AWD and 4x4 all-wheel drive (4WD), were afraid to ask, or didn't need the information. But you should know what the different things mean, even though these systems refer to the car's all-wheel drive.
So that you can understand all the intricacies of automobile drives, we suggest you watch the video from the channel Engineering Explained, which briefly tells you what AWD and 4WD drive are. If you don't know English, don't forget to turn on subtitles and their translation.
Basically ( A ll- W heel D rive - Automatic all-wheel drive) can send a variable amount of torque to each axle of the car. Usually the driver does not control this process.
That is, the electronics itself decides when and how to transmit torque to each axle. As a result, at a certain point in time, depending on road conditions, the car can have either all-wheel drive or part-wheel drive, when torque from the gearbox is transmitted to only one axle.
A 4x4 or 4WD system sends constant torque (fixed power) to each axle. Moreover, in cars with this type of drive, drivers usually have the opportunity to both turn off the transmission of torque to a specific wheel axis and turn it on.
So, how do these two types of all-wheel drive work on modern cars and why are they completely different technologies?
Typically, an AWD system uses a center differential to distribute engine torque between two axles/wheel axles. , typically rests on a transfer case, which functions as a locking differential.
You might be wondering why there is a need for both of these drive systems in the automotive industry today? After all, in the two systems the goal is the same - to distribute torque and power between all four wheels. But without these systems, the auto world would be boring and wrong.
It all depends on what kind of car we are talking about. For example, if we are talking about 4x4 all-wheel drive (4WD), then this torque transmission system is more suitable for SUVs and other vehicles that require low traction. For example, 4x4 drive is great off-road because the system sends constant (fixed) power to each wheel.
As a result, no matter which wheel has more grip, the 4x4 system ensures that each wheel receives the necessary torque. This helps prevent the car from getting stuck, which is indispensable on off-road terrain.
Unfortunately, very often 4WD (4x4) is not ideal on a regular asphalt road. The reason is still the same. This drive is ideal and most effective only off-road.
For example, when driving on a flat asphalt road, they rotate at different speeds, as a result of which the system tries to give each wheel maximum torque in order to equalize the wheel speed. This makes driving on regular asphalt very difficult and does not contribute to ideal handling.
This is why most passenger cars typically have a two-wheel drive mode (rear-wheel drive or front-wheel drive). That is, on a regular asphalt road, transmitting power to only one axle is more preferable.
The AWD system is great for road use because it can actively and automatically send the necessary power to the wheel(s) that need it most at a given time.
Some AWD systems have fixed torque split between the front and rear axles, but do not have the cornering problems of 4WD vehicles because they rely on a differential rather than a transfer case.
Of course, there are many different types of AWD and 4x4 all-wheel drive systems. But despite this, all types of AWD systems differ significantly in meaning from all types of 4WD systems.
In the channel video Engineering Explained The example used is the new BMW M5, which has an AWD system that works through various electronics and mechanical components in much the same way as the 4WD system on SUVs.
But despite this, no matter how automakers try to bring AWD systems closer to 4x4 systems, these drives, different in purpose, will still be designed for different types of cars.
