canadian_idol

what is the difference between all wheel drive, four wheel drive, 4x4, and 4x2?
thanks ....

islandpro

4x2 would be any 2 wheel drive. front or rear wheel drive

awd is kinda like 4x2. but 30% or so of your power is put to the other set of wheels. in most cases it would be split up 70% to the fron 30% to the rear wheels. normaly with awd you dont have the option of taking it to 4x2.

4x4 on the other hand will have the power divided up more even. you have the option of not using it. just going 4x2. also most of the time you also have the option to use low range. which is just a lower set of gears in the transfer case.

thats just a quick rundown

canadian_idol

okay, got it. thanks guys

islandpro

awd is nothing like 4wd. sorry

thats like saying a wrx is like a land rover... never going to happen

pr5owner

actaully in AWD systems like in the Rav4, power is split 90%/10% (F/B) and when the computer detects slippage in the front wheels it will go to 50%/50%

kc5zom

The powertrain components for an AWD and 4WD system are completely different. 4WD systems cannot vary the amount of power routed to individual wheels, an AWD system can. A 4WD system is simply a transfer case with a high and, if its a real off-roader, a low range of gearing to route power 50% to each axles, then the differential on each end splits power an additional 50%. There have been vehicles in the past with full-time 4WD (one model of the Chevy Blazer had it, long time ago) but it is a tremendous drain of power to the vehicle, hence the prevalence of AWD now.

An AWD system is extremely variable. They can transfer power from anywhere between 0/100 to 90/10 (or 100/0 in some cases) to all points in between.

hihoslva

How about this to add to the confusion:

My wife has a 1998 Cherokee Sport - the boxy one, but it's a frigging beast with the 4.0L straight six.

Anyway, she's obviously got shift on the fly 4 wheel drive (grab handle, not a button). But when you put the car into 4wd, there is a dash light that comes on and reads "Part Time". WTF? Trust me - this is a solid 4wd system, and it is NOT a torque-sensing, computer-controlled, limited slip, or any kind of torque-splitting thing. When you are in 4wd and try to cut a tight turn, you FEEL the front tires fighting it.

So why the hell would it say PART TIME? I mean, okay - it's not FULL TIME 4wd, because you can shift into RWD, but why not just simply have it say "4wd" instead?

Just seems confusing to me - there will always be things about Daimler Chrysler that I don't understand.......

~HH

kc5zom

The only confusion I have is that I can't quite figure out the point to TheMan's posts except for 4x4 and AWD being ambiguous to a person that has no understanding of cars. But this guy asking the question obviously wants an understanding of what these terms mean in the car world. Maybe the point of your original message was a little ambiguous?

kc5zom

Daimler Chrysler just needs to smoke less crack. Some dumbass marketing person probably came up with that. Be interesting to know if the new Liberty says that too. Kind of wanting one so I can have something serious to take off-road so maybe I will go look.

mito7878

I agree with TheMAN that technically its the same thing but in the automotive industry the term AWD is usually used on vehicles that have a 4WD system that cannot be turned off. The only difference between "the terms" AWD and 4X4 is the way they are used but the only mechanical difference between "The terms" is that AWD cannot be turned off to 2WD like 4X4 can. Thats why you dont see Jeeps with the AWD badge.

kc5zom

No. In the automotive industry AWD and 4WD are two different powertrain types. I'm sure "How Stuff Works" or somewhere like that probably has a good demonstration. Jeep does not use AWD because an AWD system is more complicated (extra stuff to break), more expensive, and does not have a low range. The only similarity between AWD and 4WD is that they both have the capability to place power on all four wheels. The way they do it is VERY different.

UCSBgeek

Looking on the Japanese website for Subaru, I saw that they called their cars 4WD, not AWD, it's very likely that they mean different things elsewhere, but for most of us it's what's been defined here.

islandpro

Man your kidding right something serious to take off-road. Is not a Liberty. Try a nice used or new Discovery. or at least a wrangler. not the liberty. darn thing doesnt even have a full frame under it. just like the grand cherokee. but the cherokee classic does tho.

hihoslva

Hehe - so true. The Liberty is like a minivan in sport-ute clothes. It is in NO way a "serious" off roader. A little romp in the sand maybe, but I'd take my wife's Cherokee Sport (same as the Classic - not the grand) anyday. It's a frigging beast, even bone stock. We push her truck pretty good - and it's tough as nails. I can't even consider an off-road vehicle with PLASTIC bumpers.

~HH

mito7878

You people cant just accept the simple answer so here you go

Full time four wheel drive (not to be confused with: part time 4WD ) is a system that powers all four wheels at all times. Each tire gets about 25% of the available torque. Driver has a choice of a "4-high" (that's your every day setting) and "4-low".

When "4-low" is selected the wheels receive substancially more (on a Grand Cherokee its 2.72 times more) power than in "4-high" - at the same time the vehicle moves at substancially slower speeds (2.72 times slower on J GC).

The low setting is an advantage for drivers who need to tow and maneuver a heavy trailer etc and for drivers who at one point or another may want to negotiate difficult off-road terrain.


All wheel drive is a system that powers all four wheels of a vehicle at all times as well. Difference to full time 4WD is that "4-low" is not available. Due to the lack of "low range" AWD vehicles are much less capable than 4WD vehicles.


Recently some new AWD systems have evolved. Fancy names like "Real Time 4WD" are hiding the fact that they are essentially sophisticated 2WD systems. They should be called part time AWD systems. They cannot claim the safety and traction advantages of full time 4WD. They are less capable than full time AWD systems and inferior to full time 4WD.

Here is how they work: During traction loss on the driven axle (could be front or rear) a fully automatic system (hydraulic, mechanical or electronic) routes torque to the axle with traction. This means you have to completely lose traction in 2WD on your driven axle first and THEN the other axle will take over and try to keep the car moving. So, for a moment you have 4WD. Doesn't mean much because only two wheels have traction. Once the driven axle regains traction and both axles rotate at the speed again, the system moves back to 2WD.

Examples: Honda CRV, LandRover Freelander, Isuzu Trooper (TOD), Volvo V70, 1999 Jeep Grand Cherokee (in high range