No I'm not an idiot, i know what they are but when to call them is where me and my brother fight each other.

His side is 4WD or AWD is called that when all four wheels are turning or having power applied to those.

Mine (I know I'm right ) is when there is a transfer case capable of sending power up front, it doesn't matter if it'* rear wheel drive until the rear is slipping then the computer sends power up front. He says that is not AWD, it'* just RWD.

I told him that if it has a transfer case to both axles and if it'* left in AWD, it'* still AWD if the rear axle or the front axle move the car forward. He says no, if FWD is moving hte car and there'* an axle in the back that is capable of being powered by the motor, it'* still FWD.

Your thoughts?

Well, AWD is when a car has the ability to split up the power to the wheels. If I remember right, Subaru cars have 60% or so always going to the back wheels, and then 40% to the fronts. It can adjust this as the wheels lose grip. That is what AWD is.

On the other hand 4x4 is when the power is ALWAYS split up between the wheels evenly. 25% to each wheel 100% of the time.

So him saying that the car is FWD when it has the ability to power the rear wheels, I would say he'* wrong and that it is actually AWD.

I'm about 95% sure I'm right.

4wd can be made into 2wd. awd cant, except for sti'*

AWD mean that'* 4 wheels are being driven permenantly, 100% of the time, regardless of the torque split. 4WD means that the drive wheels are selectable. 4WD only applies to rear-wheel-drive vehicles that have a transfer case, in which the power can be selectively sent to either the two rear wheels or all 4. Some 4WD systems have an AWD mode, in which all wheels can be driven on dry pavement. That'* AWD. 4WD can be AWD, but AWD can NOT be 4WD, if that makes sense. Also, there is a difference between full-time 4WD and AWD. AWD= 4 wheel torque, all the time. Full-time 4WD means that the rear wheels are driven UNTIL slip is detected, in which power is automatically transferred to the front at a pre-determined torque level, without drivers input. AWD systems vary the amount of torque that is SPLIT, but some torque is always applied to the front drive wheels, regardless of rear wheel traction.

No, on Subaru cars all 4 wheels get the same amount of power. There is no transfer case. It is almost like there is one shaft that goes from the tranny (which is slightly b4 the front wheels) that runs through the front axle to the back axle. It'* hard for me to explain, but I saw the model at the dealer.

this site is cool
http://auto.howstuffworks.com/four-wheel-drive.htm

That'* not true, subaru'* are not 50/50 torque split. The have a slightly front-biased split during driving, with up to a certain amount being transmitted to the rears as required. Yes, they do not have a REAL, separate transfer case, it'* incorporated into the transmission itself. There are ones however, such as the STi, that have a lockable center and rear differential, and that'* a totally different setup altogether.

in STIs, u have a **** to divide power from 50/50 to 0/100

Yes what I'm saying if it has a front axle then it'* a 4WD regardless if it'* being driven or not but it'* there.

But if it'* used even if it'* a 10% of total engine power, it'* AWD.

But I agree with most of you all

Maybe this was a different car maker, or an older design. I heard something like this a few years back. I don't remember for sure.


Also, Alec_b did 1000% better job explaining it than I did. I agree with what he said.