I’m looking to upgrade from a Jeep Liberty 4WD to a roomier SUV. My Jeep’s 4WD past performance has been excellent. I’m finding all wheel drive has cornered the SUV market. I’ve done Internet research on differences between the two but …I want to hear it straight from any dopers about their experiences/expertise on 4WD versus AWD.
I think it depends on what you most frequently drive in as far as conditions and terrain.
Most of the time, I am using 2 WD. I have a Dakota with a limited-slip rear-differential (both sides drive). We live in a rural area of the Kootenays of BC with snowy, icy winters, muddy springs, and rugged terrain. 4 WD is definitely an asset but I do not use it a lot.
If we lived in Vancouver, I can see where AWD might be an asset, though.
No experience on driving 4x4 full time, but AWD ford escape.
Very good driving experience with the weather we get in Ontario, first driving experience where I was not white knuckling it. AWD really shines with snow tires, but you do have a lag time between the sensor saying the wheels slipping, to the time the AWD kicks in. Its brief, but noticeable.
I just bought a 2012 escape, and picking it up Tuesday, but the one thing that I was trying to lock down with the sales people, was that 4x4 is simply a label for marketing, and it only has AWD. Unless your vehicle has a method of manually entering 4x , I would say that your getting AWD.
AWD is labeled for Cars, while 4X is now for trucks and SUV’s.
To be clear, are you implying that there is an AWD vehicle out there which has two entire transmissions - one for the front axle and one for the rear? I would love to see it.
The difference between AWD and 4WD is that the front and rear driveshafts* of an AWD vehicle are able to turn at different speeds. What this means is that regardless of conditions, at least one front wheel and one rear wheel of a 4WD system will receive power at all times, but an AWD vehicle can be in a situation where all of the engine power will drive only one wheel. This is most likely to happen when stuck in deep mud or snow, or if one tire is in the air. As mentioned above, modern traction control systems significantly blur the lines between these two terms.
*Most modern AWD vehicles use transaxles rather than a transmission, transfer case, and front axle, so there isn’t actually a front driveshaft.
A (part time) 4WD vehicle has a transfer case that is manually locked or unlocked. This controls the distribution of engine torque to all four wheels. Depending on the setup, it may deliver torque directly to an axle (in the case of a solid axle), or to front/rear differential or transaxle. Because the front and rear both receive a regulated portion of the engine output, even if one wheel slips the other axle will still have traction. A vehicle designed for true offroad operation will have a locking rear differential and a transfer case with a low range (high torque, automatically locking) mode which should not be driven on dry pavement or more than modest speed (usually <30 mph or less).
An AWD system like the Audi Quattro or Subaru Symmetrical AWD has a center differential which (in modern cars) is electronically controlled to distribute power between the front and rear transaxles. The transaxles themselves have limited slip differentials that prevent a loss of traction by limiting wheel spin. This isn’t suited to true offroad conditions (deep mud or snow, rock hopping, sand) but is quitr good on pavement or gravel in inclement conditions.
On many newer cars (and some trucks) traction contol and vehicle stability systems use the ABS system to automatically control wheel spin and limit slippage, substituting or augmenting limited slip and electronic controlled differentials. This doesn’t work well for near static situations such as rock hopping, but it worked very well for both onroad use and for situations that entail a lot of transient slippage, such as descending steep hills or sand running.
There is often considerable overlap between AWD and 4WD; for instance, the Series 80 and newer Toyota Land Cruiser (in North American markets) is all time 4WD but has low range and locking differential controls. This is true to some extent on many SUVs. Basically, if you don’t plan on driving the Rubicon trail or need to drive through deep mud and snow, AWD or “full time 4WD” without a user selectable transfer case should be fine. If you think you need that capability, you probably need to do more research.
AWD and 4WD systems have more complexity and this potentially more cost, but most of these systems are quite robust and reliable, requiring little maintenance except periodic fluid replacement and may never need repair for the life of the vehicle. I’ve had three AWD cars and never required repair on any of them for the AWD system.
No, AWD hasn’t stolen the market from 4WD. Softroad SUV used as people mover or even commuter… very common. Thats NOT the 4WD market being stolen, thats the van and stationwagon market.
We haven’t got told if you take the 4WD anywhere you need a 4WD…
Maybe you can downgrade to AWD or 2WD if its only softroads … AWD for snow ,sand, mud, 2WD if its just a road which you want a bit more drivers heigt (for vision ? ),a bit more clearance ,grippier tyres and diesel engine, a bit more suspension travel for bumpy roads, and other SUV properties …or you just want a people mover.
Well, if you just blindly plow on forward, sure. But if you consider the conditions and the capability of both the vehicle and driver (the latter being critical) then you can get impressively far over track that would be difficult to cover on even horseback or quadrunner. I’m kind of in agreement with ** harmonicamoon**; having to get out and lock hubs does give you a certain perspective on how much the trip means to you and how bad the conditions are. The shift on the fly systems that are common today are much more convenient but cause inexperienced drivers to neglect the severity of conditions, or do things like drive at high speed on unsealed roads and then wonder why they wash out on curves. Hint; you are only going to get as much traction as the ground your tires are in contact with can afford; slick ice or pools of fine sand and dust are going to be slippery no matter how many wheels are driving, and the conservation of momentum guarantees that your vehicle is going to go in a straight line about your center of mass no matter which way the vehicle is oriented unless the tires have sufficient traction.
At various points in time the auto industry has used the terms interchangeably. The definition that was once somewhat agreed upon was that AWD can be used full-time on dry pavement and 4wd is a part-time system that can’t. These days, though, that definition really doesn’t hold up because there’s lots of “full time 4wd” systems that are functionally identical to AWD, and some AWD systems only power the rear axle part of the time.
The somewhat tautological definition the auto industry’s marketing departments seem to be using these days is simply that if it’s a rugged truck-type vehicle it’s 4wd and if it’s a car or car-based CUV it’s AWD. Usually with something that calls itself 4wd, there’s an expectation that the power distribution (when the system is engaged) is going to be close to 50/50 front to rear, whereas with AWD they’re all over the place. Systems like the Subaru and Audi ones are also close to 50/50 under normal conditions, whereas many other AWD systems can only send a tiny amount of power to the rear axle or only sends any when front wheel slip is detected. The heavy front-biased or reactive AWD systems can help you get unstuck out of your driveway and such, but the 50/50 systems are much better for improving foulweather handling, both on and off-road.
I think the AWD systems even on Jeep’s little CUV’s are fairly robust, but you usually need to read down the page of the reviews to really get the nuts-n-bolts details of how they work.
Bolding mine. Is this a common term in your area? I can’t remember where you’re from, but in the US the term rock crawling is generally used to describe traversing boulder fields and the like in 4WD vehicles. Just curious.
It was a joke, basically about the folks who by SUVs and think it makes them invincible. I have been using AWD for years and while it occasionally gets me in trouble but for the most part I’d never be without it.
Still, the two most important factors in snow driving (I don’t have much experience with rock crawling) are good tires and the skill of the driver. I suspect that equipment is much more important once the terrain gets technical.