FOund this while surfing. It is an article from Difflock.com

4x4 Explained
Introduction to All Wheel Drive systems - By Eliot Lim

Buying a 4WD / AWD vehicle

My recommendations:

Avoid part time, manually engaging systems, regardless of whether it has manual hubs, auto hubs or any four wheel drive "convenience" features.


Avoid hybrid manually switchable full time/part time systems


Full time or automatically engaging part time systems are superior from an engineering point of view and gets my vote


A limited slip differential on the rear axle is a plus, alternatively 4 wheel traction control is also a big plus.


If you need four wheel drive primarily for winter mobility, a set of snow tires will make a far greater difference to overall control and traction compared to differences between various AWD implementations. If I had to choose I would rather have front wheel drive and snow tires than four wheel drive and summer tires. Four wheel drive with the wrong tires in the snow is an extremely dangerous combination.

It is unfortunate that old fashioned part time, manually engaging systems are still being sold on many SUVs today with high prices that are a match for their mediocrity. There is no reason, from a conceptual point of view that these vehicles should not have an all wheel drive system. It is this author's opinion that consumer ignorance and a uncritical media are the main reasons for the slow progress in the truck/SUV market.

It is false that a permanently engaged system is incapable of handling the rigors of off roading as well as the antiquated part time system. The Range Rover has been on the market since 1976 and it has had a full time system with a center differential since the very first one rolled off the production line. Likewise, the ultimate off roader, the Hummer uses a permanently engaged system with torsen differentials rather than solidly locked axles and part time manual engagement. Both of these vehicles are held in the highest regard with respect to their off roading capabilities.

Is he saying that a Honda CR-V or Ford Escape, or Subaru Forester is just as capable offroad as a true 4x4?

Thanks,
Tim

He must be a Lim whitt,
Catering to the people, go ahead and buy
this automatic engaging 4x4, all wheel drive
and it's better than an old fashoned manualy
opperated 4WD system  

So how are these people going to know when
the 4x4 is engaged, by the little light that tells
them so

AWD a great thing, does it have 4 Low
Will it turn 33" tires??? Hell can it turn 30"
tires  I bet not, and I'd like to see a Forrester
follow me someplace, these wannabee 4x4s are just
that, they will never be able to keep up with a Zuke,
be it a highly modified one or a stocker, stick with
a Suzuki, and don't let this guy put any doubts in
your mind.

A friend of mine has a highly modified Honda CRV
Ohh it has 215 75-14 tires and a Exhaust system
and no 4 Low, he wishes he waited for the XL-7
now, cost the same new and he got half the vehicle

I know when my 4WD is engaged, and I know when
I need 4 Low, and I know when my hubs need to be
locked and when they are not working right

All the auto this and AWD that are just that, nobody
knows when there is a problem, and if they did they
wouldn't know how to fix it anyhow, and do you really
want to take your vehicle to a   Dealer    I don't,
I don't trust those bozos to do anything right, do it
yourself and know your truck, and leave those AWD
no Low range "capable" vehicles in a cloud of 31"
(or bigger) mud tire Suzuki Dust

But that's just my humble oppinion

Wild

He must be a Lim whitt,
Catering to the people, go ahead and buy
this automatic engaging 4x4, all wheel drive
and it's better than an old fashoned manualy
opperated 4WD system  

So how are these people going to know when
the 4x4 is engaged, by the little light that tells
them so

AWD a great thing, does it have 4 Low
Will it turn 33" tires??? Hell can it turn 30"
tires  I bet not, and I'd like to see a Forrester
follow me someplace, these wannabee 4x4s are just
that, they will never be able to keep up with a Zuke,
be it a highly modified one or a stocker, stick with
a Suzuki, and don't let this guy put any doubts in
your mind.

A friend of mine has a highly modified Honda CRV
Ohh it has 215 75-14 tires and a Exhaust system
and no 4 Low, he wishes he waited for the XL-7
now, cost the same new and he got half the vehicle

I know when my 4WD is engaged, and I know when
I need 4 Low, and I know when my hubs need to be
locked and when they are not working right

All the auto this and AWD that are just that, nobody
knows when there is a problem, and if they did they
wouldn't know how to fix it anyhow, and do you really
want to take your vehicle to a   Dealer    I don't,
I don't trust those bozos to do anything right, do it
yourself and know your truck, and leave those AWD
no Low range "capable" vehicles in a cloud of 31"
(or bigger) mud tire Suzuki Dust

But that's just my humble oppinion

Wild

Well Said  

If you want a pavement pounder that will not attempt any thing moderate, much less difficult, off road, the auto systems will work.

I bet that same guy would rather have a Corvette with traction contorl so it wont slide out on him if he hammers the gas in a corner

For an every day driver that you NEVER plan on takeing off road or building for off-road use would be the only time I could see having an auto system. Auto designers are getting rediculous with the high dollar options (now turning to non option) that are for the "customers safety". Auto 4x4, traction control, AWD, etc...  I'm sorry, but I like to be incontrol of my vehicle, not have the vehicles computer control what I do. Hell they are even putting "traction control" on high performance sports cars to control wheel spin in corners So the customer wont hit the gas to hard and slide out And they consider that better than the old way of learning your vehicles limits.

All of that is so people that dont need to be driving a certain type of vehicle can do so more safely.

The Auto 4x4 systems are no were near as durable and/or reliable as the manual locking systems.

Zig

Wow, what a moron! Yes, It may be more convenient for a commuter to just have auto 4WD for the rare bad weather occasions, BUT HE'S GOT ALL THE WRONG REASON'S.  Number one the stats.  SUV's may have experienced a decline in market share, but only because they've skyrocketed in the past 8-10 years and have no where else to go but down.  Plus he's dead wrong because the SUV is the second to four door pickups in growth last year.  I'm also not sure if he's implying that AWD is more reliable, when it's clearly not.  He's definetly saying that Subaru's "a little too late to matter" AWD system is safer in case your too stupid to lock you're hubs when you see 12ft of snow in your driveway.  Neither my Trailblazer left in 2WD, or an Out back with that "wheels that slip to the wheels that...sh*t i'm already stuck" AWD are going to stop this waste of skin when he thinks he can do sixty on the thru-way in a snow storm.  As a Chevy salesman in Buffalo, NY, it's nice to tell people that their new Tracker is one of few small SUV's to offer you the safety, reliability, and durability of a full 4WD system.(I have to say few because most customers think the Vitara is a different vehicle.  This article is just proof of the statement: What the Gerneral Public doesn't know, or thinks they know...Is what makes them the General Public.

And Tim, I don't think that this guy is saying that an Escape is better off road than a Zuk.  I pretty sure that this is a consumer geared article.  This guy is just Selfish, Vain, and Cheap.  He obviously wrote this article to either justify putting his family in a KIA because he was too cheap to buy anything else, or he bought the family an Escape, cuz he felt more metrosexual in it, when his wife wanted an XL-7.  If so she should leave him immediatly, take the kids, move to Buffalo, and buy a Tracker from me

 He works for the oil companies,AWD uses more gas.             M.Z.

It all sounds like typical media hype based on opinion not fact.  I owned a 74 Jeep Wagoneer with full time 4wd so full time systems are by no means new.  However it was a dependable capable off road vehicle and I personally have no problems with AWD systems just the vehicles that manufactures put them in.  I happen to prefer a real frame and actual ground clearance.  As far as "consumer ignorance and a uncritical media" to me those are the reasons we are being forced to swallow unwanted options, systems, and high prices.  These is the same ideology that forced front wheel drive cars down are throats to the point RWD cars are nearly extinct.  NOT because there better or more soundly engineered but because somebody "smarter" than the rest of us thought that's what we should be driving and all the lemmings fell into line and jumped off the cliff.  

I'm not sure how this writer can put a Hummer and a Subaru in the same category unless its the category of

"Vehicles I've never seen wheeling"  

He's just a typical RR owner, in their opinion anything else is rubbish. A 410 or Sammi will go lots of places a RR won't, have you seen the overhang on an RR? The difflock just locks up the centre diff and makes it more like a Suzuki for off road use. As for the Hummer - ulimate off roader well that all depends on how wide the trail is, a tight twisty route through the mountains and you'd have to walk or borrow a Zuk. Land Rover/Range Rover owners seem to be the British equivalent of Jeep owners and the name of the site tells you all you need to know.

I agree, for off road driving, nothing beats a beefy part time four wheel drive.  But for trips to the mall, commuter trips, AWD is just as good, if not better.  Modern AWD systems engage nearly instantly and smoothly.  Traction control - in my opinion - works, but takes too much fun out of driving.

There are different forms of AWD.  The Subaru system applies power to all wheels all the time - good for high performance *and* poor on-road traction.  Others, as in the Honda CRV, Toyota Rav-4, and Ford Escape are primarily front wheel drive, that engage the rear wheel drive when the front tires slip - good for poor on-road traction.  Neither form is good for off road performance - there are still clutches that slip, or fluids that heat up and would cook in the rigors of off road four wheeling.

This article seems geared more towards the people who think they need a new 7,000 lb "offroad capable" suv to drive their kids to soccer practice.  While I'm all for vehicle choice, I've seen to many of these drivers get stuck in the snow out in Colorado, and many of them just don't get that while 4wd helps you speed up faster in the snow, it doesn't stop you any faster.  The rear bumper on the Toyota truck I drove through college and high school will attest to that.  

I think a large problem is that many people today know how to drive - press the gas to go faster, brake to slow down, etc. without understanding the mechanics or dynamics of what they're actually doing.  These are the people that need AWD and/or TC.  An experienced four wheeler understands the way the vehicle operates, and would be hampered by these systems, especially traction control.

For snowy roads, unless the snow is quite deep, I'd much rather have my Subaru WRX than my Sidekick.  The Sidekick will get through deeper snow, but the Subaru's viscous coupling rear and center differentials will take all other conditions with much more control and stability and quite a bit more speed.  The WRX does not have traction control, so it's still possible to get wheel spin - you just spin all four tires.  Which can be a bad thing for people not used to it, the turbo kicks in strongly at 3000rpm, and on snowy/icy roads, can instantly break all four tires loose.  

Just my (opinionated) 2 cents.

- Craig

I'm not sure how this writer can put a Hummer and a Subaru in the same category unless its the category of

"Vehicles I've never seen wheeling"  

You don't have a Subaru Off-Road club ripping up their vehicles in your area?  

I believe that the article writers view of off-road is really unmaintained roads, and newer ones at that.  

As for the WRX, Subaru has said several times that they will not be  building a traction control system as a properly designed limited slip setup is superior in every way.  At least I think I read that as a quote somewhere.

I agree, for off road driving, nothing beats a beefy part time four wheel drive.  But for trips to the mall, commuter trips, AWD is just as good, if not better.  Modern AWD systems engage nearly instantly and smoothly.  Traction control - in my opinion - works, but takes too much fun out of driving.

There are different forms of AWD.  The Subaru system applies power to all wheels all the time - good for high performance *and* poor on-road traction.  Others, as in the Honda CRV, Toyota Rav-4, and Ford Escape are primarily front wheel drive, that engage the rear wheel drive when the front tires slip - good for poor on-road traction.  Neither form is good for off road performance - there are still clutches that slip, or fluids that heat up and would cook in the rigors of off road four wheeling.

This article seems geared more towards the people who think they need a new 7,000 lb "offroad capable" suv to drive their kids to soccer practice.  While I'm all for vehicle choice, I've seen to many of these drivers get stuck in the snow out in Colorado, and many of them just don't get that while 4wd helps you speed up faster in the snow, it doesn't stop you any faster.  The rear bumper on the Toyota truck I drove through college and high school will attest to that.  

I think a large problem is that many people today know how to drive - press the gas to go faster, brake to slow down, etc. without understanding the mechanics or dynamics of what they're actually doing.  These are the people that need AWD and/or TC.  An experienced four wheeler understands the way the vehicle operates, and would be hampered by these systems, especially traction control.

For snowy roads, unless the snow is quite deep, I'd much rather have my Subaru WRX than my Sidekick.  The Sidekick will get through deeper snow, but the Subaru's viscous coupling rear and center differentials will take all other conditions with much more control and stability and quite a bit more speed.  The WRX does not have traction control, so it's still possible to get wheel spin - you just spin all four tires.  Which can be a bad thing for people not used to it, the turbo kicks in strongly at 3000rpm, and on snowy/icy roads, can instantly break all four tires loose.  

Just my (opinionated) 2 cents.

- Craig

I SO want a WRX.

I SO want a WRX.

I love it!  More power than I need, great traction, stable in turns, decent economy, and lots of room.  I just wish that the insurance on the WRX was as low as the Sidekick's.

I find that I drive the Sidekick about 50% of the time, the contrast between the two different vehicles keeps driving interesting.

- Craig

Suzuki 4x4....it's true.

All I want from the WRX is the EFI system  

Wild