四輪駆動アイスランド

Four-wheel drive is a drivetrain system that can send power to all four wheels of a vehicle rather than only the front or rear wheels.

4x4 normally indicates a vehicle with four wheels of which all four can be driven by the powertrain.

The terms 4WD and AWD are sometimes used interchangeably, but manufacturers often use them for different types of system. Traditional 4WD systems commonly provide selectable driving modes, while AWD systems often distribute power automatically.

Yes. Sending power to more wheels can improve traction when accelerating on snow, mud, gravel, sand or other low-grip surfaces.

Not automatically. Braking performance depends primarily on the tyres, road surface, speed, braking system and vehicle condition. Four-wheel drive should not encourage a driver to travel faster on slippery roads.

Yes. The tyres provide the contact between the vehicle and road. Four-wheel drive cannot compensate for tyres that are unsuitable, excessively worn or incorrectly inflated.

Yes. It can improve the ability to move away and climb on snow-covered roads, but safe braking and cornering still depend heavily on tyre grip and appropriate speed.

Some 4x4 vehicles are designed for off-road use, but four-wheel drive alone does not make every vehicle suitable for difficult terrain. Ground clearance, tyres, suspension and the drivetrain design are also important.

This depends on the type of drivetrain. Permanent or automatic systems are designed for normal road use, while some selectable 4WD systems should only be engaged under particular conditions. Follow the manufacturer's instructions.

It can improve traction when towing, but the legally and technically permitted trailer mass is determined by the vehicle's approved towing limits and local regulations, not simply by the presence of four-wheel drive.