Hey, friends.
It's Len here from 1A Auto.
Today, we want to talk to you about the difference between all-wheel drive and four-wheel drive
slash 4x4.
Let's take a second and get into it.
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Let's get started.
So, let's just do a brief talk.
And I say brief because it's very short about the differences between four-wheel drive and
4x4.
4x4 vehicles would essentially mean that you have four wheels, and all four wheels are
getting powered at the exact same amount of speed/power.
If you have a four-wheel drive vehicle, that doesn't necessarily mean that you have only
four wheels, you could have six wheels, we could have eight wheels, we could have infinite
amount of wheels, but four of those wheels are actually powering the vehicle.
So, now we're gonna talk about all-wheel drive.
If you have all-wheel drive, then that would mean that all of your wheels are actually
being powered by the vehicle at the same time, but the amount of power can actually change
depending on the circumstance at hand.
So, let's just do a quick demonstration so you can visualize what it is I'm talking about.
If you look right down here on the whiteboard, you're gonna see a two-wheel drive model for
a vehicle.
This one go with the assumption that you have a rear-wheel drive vehicle because you would
have your engine which is in black, your transmission, your rear driveshaft, and then, of course,
the rear differential with the axles inside powering those wheels.
And then, of course, you have your front-wheel-drive vehicle here, which would have your engine
in black, once again, your transmission, and you would have the axles that come out of
that transmission going to the driver's side, and then either under or behind, maybe even
in front of the engine going over to the passenger's side.
If you were to move along, you're gonna see a four-wheel drive or a 4x4 model.
With this, you're gonna have your engine powering your transmission.
The transmission is gonna put that power to the transfer case.
Now, here's where you'd have to decide whether you want two-wheel drive, which would come
back here only and power just the rear wheels, or a four-wheel drive, which would of course
send power also up to the front differential, which is located right here.
And then it would power the front wheels at the same time as the rear.
If you're in four-wheel drive, your engine would power the transmission, like I said,
power up that transfer case and the transfer case would send the same amount of power to
the rear driveshaft and the front driveshaft at the same time, meaning that all four wheels
would have the same amount of power.
Well, that's great, unless of course, you're on regular road situations or dry situations
because you'll have binding and you could potentially damage your transmission, your
transfer case, or even those differentials slash axles.
Now, we're underneath the four-wheel drive vehicle.
And as you can see, we have our front differential up in the front here, you have your front
driveshaft that leads to that transfer case, and then from the other side of the transfer
case, it's gonna lead to the rear driveshaft that leads to the rear differential.
All that is gonna be powered by the engine, which then powers the transmission right there
which is connected to the transfer case.
When this happens and the transmission is telling the transfer case to go ahead and
add power, if you have your vehicle in two-wheel drive, it's only gonna put power to that rear
driveshaft, which will turn only the rear wheels.
If you were to put it in four-wheel drive and you're on dry pavement, it's gonna activate
both of the driveshafts, front and rear, and it's gonna turn them at the exact same rate.
The problem with that would be is if you're on dry pavement, and you're turning the wheel.
Overall, as you're turning, of course, the outer wheels are gonna be turning faster than
the inner wheels.
When this happens, you're gonna notice slipping and binding and all sorts of funny reactions
coming through the steering wheel and probably jolting inside the vehicle itself.
And that binding is gonna occur right inside the transfer case.
Now, obviously, having a four-wheel drive vehicle like this is gonna be exceptionally
useful in cases where maybe you're off-roading, in slippery circumstances, going up a hill
and the traction just isn't there where you need to be, you'd be able to shift into four-wheel
drive and have all four wheels gripping.
Maybe you're driving in some snow, obviously, you don't want to be slipping all over the
place, you're gonna need that extra traction, you just slap it right in four-wheel drive
and you'll have four wheels pushing you wherever you need to go.
If you were to move along to the all-wheel drive model, you're gonna have your engine
and usually, it's front to rear but sometimes it can go side to side, it's really vehicle-specific.
You're gonna have your transmission slash front differential unit.
The transmission is blue and the front differential, which is part of the same unit is gonna be
in red right there.
That's gonna power those front axles.
At the same time as it's powering the front axles, it's gonna be powering the rear driveshaft,
which then in turn powers the rear differential.
Now, if you are in a slipping condition, when your vehicle is slipping, that's gonna overall
put power to whichever wheel that it decides.
Some all-wheel drive vehicles, like I said, will actually put the power to whichever wheel
is slipping, which really doesn't make very much sense.
And then in vehicles with VDC or vehicle dynamic control which uses the ABS like I said before,
it's gonna be able to determine if there's a wheel slipping, it's gonna make sure it
applies the brakes, it's probably gonna pulsate a little bit on the brake pedal, apply the
brake to that one wheel that's slipping or even multiple wheels that are slipping and
transfer the power specifically to the wheels that it determines has the best amount of
traction to get you on the way you need to go.
Now, obviously, having an all-wheel drive vehicle is probably better for most people
in passenger vehicles.
You're gonna probably be driving around longer distances more than likely on paved roads.
If you have an all-wheel drive vehicle, it's gonna come in handy, especially in slippery
circumstances such as rain or snow, or even off-roading conditions.
One of the best things about all-wheel drive systems is they can divert the power not only
from the front to the rear, but they can also divert power overall from side to side if
they needed to, especially if you have electronic BDC control, which would be vehicle dynamic
control.
The way that that essentially works is by activating the brakes through the ABS unit.
When the computer decides that there's one wheel slipping, it can sense it by the ABS,
in which case it will apply the brake a little bit on that wheel, and it'll divert the power
to the wheel that is not slipping, or the wheel that is gripping.
Now, it's important to remember that not every all-wheel drive vehicle is the same.
Some of these vehicles will have most of the power going to the front and about 20% going
to the rear.
Other all-wheel drive vehicles will be approximately 50/50, depending on the circumstance.
And then even on newer vehicles, something like a supercar or whatnot, you might be able
to go ahead and push a button and it's gonna go ahead and change the vehicle from all-wheel
drive super grippy to a rear-wheel drive mostly super slippy, which would be the fun mode
button.
Now, on all-wheel drive vehicles, what you're probably gonna notice is it looks a little
funky.
You have the area that comes from the engine over here, and then it would go to approximately
where the transmission is.
And that would be this giant unit right here.
With the all-wheel drive, what they did is they incorporated the front differential in
with the transmission.
So, even though the engine is turning the transmission and the transmission is turning
the differential and then, of course, the other differential down there, it's all kind
of incorporated into one unit here.
Now, this is just a manual transmission.
If you had an automatic transmission, it's probably gonna look a little bit different,
but the overall function is gonna be about the same.
So, now that we know about what the driveline systems look like, let's talk about their
intended purposes.
If you were to look at the two-wheel drive models, you're gonna see you have your rear-wheel
drive and your front-wheel drive.
Well, the rear-wheel drive, of course, is gonna be probably more for a performance type
of vehicle, maybe something like a Mustang or a Camaro or something like that where you
want lots of power and maybe be able to spin those back tires and have a little bit of
fun.
Not that I recommend that.
So, now let's move across to the front-wheel drive vehicle.
This is, of course, gonna more than likely be a little bit lighter of a vehicle.
It doesn't necessarily have any of the driveline that leads to the rear or a rear driveshaft
slash differential.
So, of course, it's gonna be a little bit more economical for you.
You're probably gonna find that in the vehicle that you commute in, maybe something like
a nice Toyota Corolla, which are great vehicles, by the way, and you're gonna have much less
fuel consumption with those like I was saying because it just doesn't weigh as much, there's
a lot less functioning parts in it.
If you were to move along to the four-wheel drive/4x4 models, as you can tell, there's
a lot of moving parts that are involved just to get the vehicle to move.
It's gonna weigh a lot more because this weighs a little bit, that weighs a little bit, little
bit, little bit, little bit.
It's gonna weigh more.
It's gonna go through a lot more fuel just to drive the vehicle.
But of course, it does come in handy if you're in low traction situations.
Now, if we were to move along to the all-wheel drive vehicles, which in my opinion would
be the most versatile vehicle.
Reason why I say that is because you can use it in dry situations, you can use it in low
traction situations, you can go for long trips, short trips, on road, off-road, you can do
pretty much anything you want.
So, in my opinion, all-wheel drive is the best of both worlds.
So, like I said, there's a lot of things that you have to think about when it comes time
to choosing your driveline system, whether it's going to be two-wheel drive, four-wheel
drive, or all-wheel drive.
You just have to think, "Am I gonna be driving on dry pavement, down a straight line or maybe
highway driving?"
You could probably go with two-wheel drive.
If you're gonna be driving in areas where it's loose dirt, maybe dirt roads constantly,
driving up mountains, or a lot of frequent off-roading, you'd probably like to have the
ability to have four-wheel drive because it is nice to have all four wheels pushing you
up that loose traction dirt road.
Now, when we're talking about four-wheel drive vehicles, there are a lot of different types
of four-wheel drive systems.
You might have something that you have to turn a little knob to switch it to four-wheel
drive, maybe a push button or maybe even that lever down there that you got to really jimmy
to make it shift into four-wheel drive.
Overall, the four-wheel drive high function is great if you're driving on regular roads,
as long as they're wet or at least semi slippery.
You definitely don't wanna drive on dry pavement that way, as opposed to all-wheel drive where
it really doesn't matter what type of pavement you're driving on.
The four-wheel drive low is for low-speed situations.
That's for when you need the most amount of traction and the most amount of torque getting
to the ground.
It's gonna limit the amount of power that's coming from your engine and basically transfer
it.
So, even if your engine RPMs are high, it's gonna still turn those wheels slow.
It's just gonna apply it as torque.
And so that way there, you'll get the most amount of grip into whatever you're supposed
to be gripping, whether it's dirt or snow or whatever, and it's gonna give you that
power to climb out of it.
But once you're out, you need to make sure you stop and either shift into four-wheel
high, or even two-wheel drive, depending on the situation.
With all-wheel drive, you don't necessarily need to do any shifting from two to four even
for low, it pretty much does everything for you.
Continuing on with talking about four-wheel drive is just because you shift your vehicle
into four-wheel drive, doesn't necessarily mean that all four wheels are gonna have the
same amount of power going to them at the same time.
The power is still gonna come from your engine to your transmission.
From the transmission, it's gonna go to the transfer case.
At that point, when you're in four-wheel drive, the transfer case is gonna say "Okay.
You and you, turn same time."
And that's great.
The front and rear driveshafts are gonna be turning at the same time.
But once it gets to the rear differential or the front differential, the pumpkins, that's
where the magic happens.
And this is where things can change up a little bit.
It really depends on what type of differential you have.
Because if you have a locked differential or a positive differential, that rear differential
is gonna be turning both the axles at the same time, no matter what.
Even if this left rear wheel for some reason was off the ground, it's still gonna wanna
turn.
If it was an open differential or even a limited-slip differential, what you're probably gonna notice
is that wheel that's up or doesn't have as much traction is gonna wanna spin, but the
one that's on the ground isn't really gonna do much of anything, even though it's getting
the power coming from the transfer case slash drive shaft that leads to it.
So, now inside of a limited-slip differential, you're gonna have these little clutches that
are attached to both of those axles.
And what happens is, is when the vehicle realizes that they're slipping, whether it be from
one wheel or the other, it activates those clutches, and it's gonna make it so they both
wanna turn so that way there you'll have extra traction.
Like I said, those clutches can wear down.
And usually, there is an additive that you'd wanna use inside your differential.
Now, having limited-slip differentials is gonna come in handy, especially if you're
driving on road mostly.
If you're driving off-road, more than likely, you're not gonna wanna go with a limited-slip
differential because it's gonna be having a lot of pressure under it at almost all times
and it's gonna wear out those clutches very fast.
Now, if the vehicle that you're gonna be driving is mostly for off-roading slash bumpy off-road
conditions, you're gonna wanna go with a posi-traction rear differential.
All right.
Friends, so we try to give you an informational video on the difference and driveline systems,
whether it's two-wheel drive, four-wheel drive, or even all-wheel drive.
If you have something to say, leave it in the comment section below because I'd love
to hear from you.
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