I personally think that both systems are great and they both have advantages over
front wheel and rear wheel drive systems. Through research I've noticed that 4wd vs awd
is a long and complicated topic so I'm going to keep it as simple as possible.
Basically, both systems are there to supply torque to all four wheels of the vehicle
allowing it to drive in adverse conditions on and off road where two wheel drive vehicles would most certainly have
Both terms are sometimes used interchangably but a simple way to explain both drivetrains is by saying that
the Four wheel drive operates on two wheels (usually the rear) and you have to put the vehicle in four wheel drive
mode whenever the terrain requires it.
All wheel drive usually functions without dedicated switches. There are systems called
automatic all wheel drive which usually functions as a two wheel drive (usually the front) in normal conditions but
traction is constantly monitored. If the driven wheels lose traction then torque is sent to the
other wheels. This is automatically done without the need to use any dial or switches.
Now you may think that the All wheel drive is better as power is always being sent to the four wheels but there
are some trade offs with the two.
All wheel drive vehicles are better for every day driving. Considering that many all wheel drive
vehicles have some form of traction control they work well to keep the
vehicle stable on snow or other adverse conditions on the road. Most all wheel drive vehicles are designed
to provide maximum performance on road or on a track.
Four wheel drive vehicles function as rear wheel drive during everyday use as it is not recommended
to use the four wheel feature for everyday driving. The advantage of four wheel drive is noticed when you
take the vehicle off road as this is what four wheel drive is made for.
This is achieved because there are different ranges (gears in the transfer case)
on the vehicle to allow greater functionally in adverse conditions in the lower range. The low range has a similar
concept to the low or soft gears of a mountain bike.
All of the four wheel drives that I know of are vehicles with a high
ground clearance so they can easily go through rough roads, deep holes, flood and other obstacles
associated with off road terrain.
New technology such as traction control has improved both systems in many ways and now there are many
high rise all wheel drive with above average off road capabilities but these vehicles usually have a high
The systems are important because if only one wheel remains with traction as the vehicle is
climbing a steep hill, the amount of torque that is usually sent to one wheel may not be enough to move the
weight of the vehicle. The system will detect that only one wheel has traction and send more power to the
wheel with traction until it detects traction on the other wheels.
So 4wd vs awd, I must tell you that both systems have their limits and drivers of these vehicles should
still exercise caution as all four wheels could lose traction, the possibility is slim but it could happen.
Systems improve vehicles but not to perfection so be mindful.