AWD vs 4WD

AWD is the same as 4WD, if you have 4 wheels, that is!

I gave you a good rating and what you said was absolutely correct!

BUT!!

What you did not mention was that a different vehicle, with maybe different tread/tires could still get problems in spite of everything else being similar or equal!!!

Generally the biggest issue with traction 4WD or AWD is less to do with the drive system and a heck of a lot ore to do with tires.

I recently had to traverse a dirt road up into the moutains of southern Kentucky. When things were cold this was no problem, my rental Nissan Pathfinder had no trouble scampering up and down these tracks as everything was frozen up and / or dry. Once it warmed up and the dirt melted then it got.... Interesting.

On the night in question I got about half way along and arrived at teh bottom of a switchback. The track got steep right here and there was little in ght eway of gravel put down to help.

Despite selecting low range and 1st gear, there was no traction, solely due to the road tires that Enterprise had on the vehicle.

10 minutes later a colleague with an F150 and proper off-road tires came along and we traversed the grade (almost burned up the transmission doing it but that's another story).

In another example in my old home we had a steep grade leading to the sub-division. My neighbour managed to lose traction in his BMW X5 while my old Reuault 21 made it up and down no problem. Of course, he was an idiot that didn't know how to drive, assuming 4x4 meant "I'll go wherever the heck I like" not realising you really do need to know how to drive in snow and ice. And practice it too.

There are various strategies and techniques used to implement both AWD and 4WD and depending on vehicle. Either could be capable of satisfying your requirements depending on system. Usually the difference between the two is that AWD is typically a full-time system where 4WD is an on-demand system. I said typically as there are probably example which break this rule.

FYI some vehicles come with a down hill descent feature which pretty much do what you were manually doing by putting your vehicle in low.

Shawn

To elaborate on what was already said.

4x4 is a positive connection between the front and rear differentials. It is selectable because it simply would not last or be practical as a full time system. It needs to be run on slippery surfaces or else it puts tremendous strain on the drive train components.

AWD uses either a clutch or coupling of sorts (likely viscous) to connect the front and rear differentials. Clutch types will engage once a slip occurs and couplings transfer torque to the side that is not slipping during a loss in traction. The make / model of vehicle makes a big difference here.

Basically 4x4 is most effective, but traction (your tires) are #1.

If OEM 4x4 or AWD and good tires aren't enough and you need more traction. You'll need to look into locking rear and front differentials. Lockers should only be needed if your climbing mountains or travelling through mud bogs. They will compromise safety on dry roads (they can cause issues turning) and can be dangerous on snow/ice (if you cause all 4 wheels to slip at the same time your "officially" out of control.

As stated elsewhere, alot of this is going to depend on the car and how its setup.

I drive a 4wd chevrolet chevrolet suv and my girlfriend drives an AWD Subaru SUV, both of simelar weight, although the subaru has a bit more power. Both of us agree the chevrolet gets better traction in the snow and ice then the subaru, and living in the northeast US we've certainly gotten a lot of snow and ice this season (the day before yesterday we got 8", quite a bit for this late in winter). The chevy's tires arent nearly as good as the one on the subaru on top of that. The chevy is superior to the subaru in climbing hills in bad conditions as well. This isn't just my opinion - she regularly asks me if she can take the old beatup chevy over her new subaru anytime the weather gets messy (it used to be her old beatup chevy, now its mine).

There are other advantages and disadvantages to each type. One advantage of 4WD over AWD is you can change out your gear sets more easily, both in your axels and your transfer case, particularly if you're driving an american made 4WD, changing up your torque or rpms. However, while in 4WD typically the car will not corner nearly as well as an AWD vehicle, will have higher fuel consumption then a simelar AWD car, and may be speed limited. On the other hand, switching the 4WD car into 2WD (as far as I know this is something you cannot do with an AWD car) will rectify these issues.

It seems to me that there is a trend of which type is used based on the car. It seems AWD is used more on cars and smaller SUVS whereas 4WD is used more on the larger trucks and SUVS...perhaps its a matter of required ground clearance? Or maybe there are more profound fuel economy reasons?

Avery Montembeault

Answer - Yes or No

The obvious question would be what vehicle are you considering. The golden rule of ice and snow driving is "thou shalt not touch the brake even gently" - and rule two - when in doubt refer to rule one. ( obviously there are exceptions to every rule but remember rule 2 )

Several factors come to mind in my experience with Jeeps, 4x4 and AWD systems - Tire foot print (width of tire on road) - Tire tread ( winter/ summer / AT. . .) - Manual or Automatic trannys - chain or belt driven/controlled transfer case - Full lock or limited slip differentials - Weight of vehicle - Wheel base of vehicle ( How long from front wheel to rear wheel on same side) - Number of gears available.

Now with all that in mind if your Tire foot print, transmission set up, vehicle weight and wheel base remains the same the only remaining question is what version of AWD do you have - Some are full lock , some limited slip, some are traction control.

Traction control units can (CAN) get fooled by ice and would not function as your older 4x4 in most cases as it redistributes power wheel to wheel and adjusts braking also ( refer to rule one ) the problem is compounded usually with the earlier AWD traction control systems, the more contemporary units available now over come this to some extent.

limited slip styles where the AWD is a function of a locked transfer case providing power to all wheels allowing for traction from tire to tire may in fact function as your 4x4 because your 4x4 may be a limited slip itself ( many 4x4 are really limited slip as anyone will confirm to seeing a truck with two wheels up in the air one in front and one back spinning under engine power whilst the ones remaining on the ground are still)

If it is a full locked system it most likely, with all things being equal function as your current rig. Again it all depends on your rig now compared to your future AWD rig.

So as muddy as the answer seems, it is in fact the only answer available.

If you could tell us what rig you are driving now and what rig you are thinking of getting I can get a lot more specific.

Traction (in my experience) the more important stuff is footprint and wheelbase and weight in order. Throttle application and breaking habits are next

So let us in on some additional data and we can narrow the answer to your application. You should also know this has been an old crusty 4x4 discussion years and years as to the benefits of AWD vice 4X4 lock in and opinions are plentiful as to the benefits and detractions from both camps abound and your mileage may vary.

Why would any of this be of interest to you if you have ABS (Anti-lock Braking System) that is working as it should?

ABS alone will not help, except to stop, not to go. You also need ESP as well or one of its derivatives (Mitsubishi Traction for example) if you are to climb steep slippery hills......

The only direction referred to in the question was down, not up the hill. Now if he is trying to go up the driveway, I would suggest a snow shovel and a load of rock salt.

I was silly enough to think that he might want to also drive home occasionally, how stupid can I get?

I'm thinking if he uses the snow shovel and salt his wife and kids might make it home too.

On ice or packed snow ABS will not help, in fact it is more trouble than not having it at all.

......or loose grit etc..

But I would not say it is more trouble, if those last couple of yards were extremely important!! maybe you should drive much slower, especially when knowing about this and those conditions prevail!!

But, ABS was not really designed to help under such conditions and is still for "Amateur Drivers" better for them than without! At least the car stays better in balance!!

It is better for most people to have it available probably more than 90% of the time they are driving.....some even 100%, always when wet or dry for example on a tarmacked road....

Only experts can really stop better under such conditions as you mentioned with it switched off (assuming there is such a switch, in my last 8 cars, ABS was always on, only ESP could be turned off an on......!)

The biggest problem with ABS is if in panic, the driver wrenches the wheel hard over, he may leave the road (as ABS will allow him to do just that) and cause himself a worse accident than the situation on the road would have given him had he just braked in a straight line as best he could.......as one did without ABS years ago.....!

When ABS first came on German cars generally, the insurance companies loaded up those cars with a 28% penalty for some years as these cars were often in worse accidents than similar cars without it!!! The same went for AWD cars too for a period!!!

I have driven on sheets of ice before in Kentucky after an ice storm. Believe me when I say that there is no 4 wheel drive or AWD that is a match for black ice. The only thing that might help would be studded tires.

Slow steady power application/removal planning far ahead, large footprint of tires aggressive tread and weight of vehicle - if all these are constant it is then that AWD 4wd comes into play and the various systems combined. Two of the scariest add ons for this crusty 4x4 enthusiast are airbags and abs. A trick employed by OTR truckers is drag a wheel in the dirt usually done on roads that have wide shoulders and is effective except when you have heavy snow cover. The advantage of 4x4 on ice is after you exit the street you can run back up to it afterward . . . and 4 locked in paws clawing at the road surface is sometimes better than two.

The reason for my fear of airbags and abs is a muddy hill dotted with trees off grade and steep enough to see yer belly button when you look down grade.

Its been years since I have been punched in da face so i don't want my shinny new rig to do it to me either. Steps to prepare my rig for off road beyond the normal maintenance are lock hubs, air down tires, check washer fluid, check winch, disable airbags In that order.

Whoa up there stop take a breath let yer tires cool then git back at it...

I have a 2006 Jeep Grand Cherokee 4x4 with 3.8L V6 and it is usually loaded, in mountains in Canada and Donner Pass in California with ice/snow load it bottomed some. But I also got lucky by running up 101 when the Grapevine was iced over in January, I bought a pair of tire chains in San Jose, CA before return trip to WI the end of January. This Jeep doesn't care what the road looks like, lets go, with highway tires all around. To turn go easy on the gas, if too much gas it goes straight on slippery ice. About 50,000 miles in the last year, writing this from Orlando, FL.

I also had a new 1986 Ford Bronco II with electric-locking 4x4, this was a ball to drive because the gas peddle helped with steering. No gas it didn't turn on ice/slush, hit the gas easy and the front tires pulled it around the corner. Got passed by a front wheel drive Dodge on the New York Thruway in a snowstorm, also broke trail thru 6 inches of new snow, ran snow tires on all wheels year around. 60,000 miles in 4 years. Also drove on a lot of icy roads.

Otherwise I really prefer front-wheel drive for winter, but some have poor start traction even with Blizzak tires, but once rolling my 2003 Ford Focus has gone almost 200,000 miles thru a lot of winter weather across North America from Chicoutimi to Fort McMurray to San Diego, Orlando and Dartmouth-Halifax, N.S.

Having also driven 3 more mid-size front-wheel drive cars to 200,000 miles since 1991 driving mostly in WI, MN, N&S Dak, N-IL, and UP MI.

I've not been pulled out or stuck since 1966 when driving my 1960 Ford 4-door rear wheel drive when I dropped a tire off the pavement and got "sucked" or pushed into the ditch by my studded snow tires.

Slow down, think about what you are doing and be careful. Hindsight is usually 20/20 and anyone thinking they are in control on ice is headed towards disillusionment...

Well from an enthusiast point of view if you haven't been stuck you haven't been 4x4. The physics of driving these kind of rigs as I stated before is a very dynamic environment. My front wheel drive rabbit would drive through mountains of snow, front wheel diesel power trucking along at 40mph. After all I cut my driving teeth in the mountains of Bavaria, you haven't lived until your doing 70mph at 15 yrs old around a corner in a Nova on a slick mountain road and you feel "in control". Operative word was "feel".

My Grand Wagoner 345,000 miles, my Jeep CJ7 275,000 (new motor and tranny), My Ford Excursion 70,000 (its a 2006), my Ford F350 4x4 pickup 90,000 have all been foul weather drivers in addition we go looking for trouble with the Wagoner (what a great vehicle) and the Jeep and my pickup. I finally gave my son my VW rabbit and it went on for about 100,000 miles more before he killed it. The Jeeps went to Cold Lake in Canada, stayed for a while while we lived there and made it back. So we spent some time in the great white north.

The original question was will it act the same. The answer was a resounding maybe. Too many factors. As a rule the AWD of today is pretty good stuff so yeah it should but your driving style will have to meet the vehicle. I certainly don't drive my F350 Diesel 4x4 lifted 10" with 42" tires like I do my Jeep with 36" tires. If I did my Jeep would demonstrate its ability to float (unintentionally) and my F350 would eventually get its top torn off. My Jeep is about throttle control, My Ford 350 is about low end torque and muscle they require such a different driving style. My Excursion also a diesel is our highway family mover and its 4WD system is required to execute that mission when needed as well as allow my wife a Realtor to drive to places some of us wouldn't take our BMW's it is flawless at that task. It did shine when we were coming through Kentucky in an ice storm with a steady anticipative response in snow and ice that formed on the roadway it also did well hanging a wheel off the track when it got real rough because of its weight and more street like tires ( less aggressive and not as wide as my other rides) .

Many of us have our trail stories and our favorite rigs - but all things being equal its you the driver that determines if it goes and how it goes is how familiar you are with your ride. As if to illustrate my point we had an old dude (read: older than me ) that took an old Ford Station wagon out to where only 4X4 would dare go, he bagged his street tires and went pretty much anywhere we did in our Jeeps and other 4X4 style vehicles. So its really a matter of how well you know your rig and its a smart person that asks questions like the one that originated this thread.

Refer to the other posts on this and again all things the same if it is a more modern vehicle that AWD rig should be cool enough and most likely will get you in and out of your driveway.

Thats it, all this 4WD talk has made me decide a trail ride is in order at lunch. Its been raining a lot here and I should be able to find some pretty good trail to goof off on. Tread Lightly. Take out more than you bring in. Enjoy