WSZYSTKO o napędach AWD i 4WD | Quattro / xDrive / 4MATIC / Subaru - który najlepszy?

Summary

The script provides an in-depth look at AWD/4WD systems. It explores the intricacies of differential gears, limited slip differentials, transfer cases, center differentials, and more. Tracing the evolution of Quattro, xDrive, 4Matic, Symmetrical AWD, and S-AWC, it analyzes the strengths and weaknesses of various manufacturers' approaches. While technical at times, analogies help explain complex concepts effectively. Ultimately, it crowns the highly advanced, computer controlled S-AWC system of the Mitsubishi Lancer EVO as a masterpiece of AWD engineering.

Takeaways

• 😊 The video provides an encyclopedic overview of AWD/4WD systems and how they work.
• 🔧 It explains differential mechanisms like open diffs, limited slip diffs (LSD), torque vectoring, viscous couplings, etc.
• 🚙 It talks about AWD/4WD systems from various manufacturers like Audi Quattro, BMW xDrive, Subaru Symmetrical AWD.
• ⚙️ Subaru's symmetry in drivetrain layout gives it great handling balance.
• 💪 Mitsubishi's Super All Wheel Control system in the Lancer Evo is very advanced.
• 🔬 The video analyzes the strengths and weaknesses of different AWD systems.
• 🛣 Audi's system is great on road but has front weight bias.
• 🏎 BMW's xDrive allows power transfer front to rear.
• 🧱 Different systems have different applications like off-road vs on-road.
• 🔋 The future is individual wheel drive using electric motor at each wheel.

Q & A

What are the main differences between AWD and 4WD systems?

The main differences are: AWD systems have a center differential that constantly splits torque between front and rear axles, while 4WD systems can disconnect the front axle and send all torque to the rear. AWD is better for on-road driving, while 4WD is designed more for off-road use.

What are the advantages and disadvantages of a Torsen differential?

Advantages of a Torsen differential are: fully mechanical so no electronics needed, robust and reliable, can vary torque split between wheels. Disadvantages are: heavy, adds drivetrain losses hurting fuel economy, must be mounted behind transmission.

How does a viscous coupler limited slip differential work?

A viscous coupler LSD uses silicone oil between two sets of plates. At low speed differences between plates the oil flows freely. But at high speed differences, the viscosity increases, which clamps the plates together, locking the diff and sending more torque to the wheel with traction.

What is unique about Subaru's Symmetrical AWD system?

Subaru's Symmetrical AWD places all drivetrain components, including the longitudinal engine and transmission, along the car's centerline. This provides a low center of gravity and balanced weight distribution for excellent handling.

What advanced technologies are used in the Mitsubishi Lancer Evo's S-AWC system?

The S-AWC system uses an active center differential, active rear differential, and yaw control system that work together to vector torque and enhance cornering. It also integrates with stability control and ABS.

How does an open differential work?

An open differential allows the left and right wheels to spin at different speeds by using spider gears in the differential. But it divides torque evenly at all times - it does NOT send more torque to the wheel with less traction.

What is the benefit of a locking differential?

A locking differential can lock left and right output shafts together. This forces wheels to spin at the same speed, allowing full engine torque to be applied to the wheel with traction, which is useful for off-road driving.

What is the advantage of BMW's xDrive system?

xDrive uses an electronically controlled multi-plate clutch differential that can actively vary front/rear torque split. A key advantage over Audi's system is xDrive does not have to be connected directly to the transmission.

How does a Haldex AWD system work?

The Haldex is an electronically-controlled clutch pack that can engage AWD on demand. It disengages AWD during normal driving for efficiency. When slip is detected, a pump pressurizes the clutch to divert torque to the rear wheels.

What is the future of AWD with electric vehicles?

Future EVs can use independent wheel drive (IWD) with a motor at each wheel and torque vectoring between wheels for ultimate traction and handling.