4x4 vs. AWD vs. 4-wheel drive ?

[Phi]

I've got a ridiculously dumb question I'm in the mkt for a used Tundra (2000 V8 Access Cab)and a bit confused about whether there is a difference between 4x4, AWD and 4-wheel drive? The terms seem to be used interchablebly. Are they the same? What should I be looking for to differentiate? Thanks in advance and keep on truckin

[brink]

From what I understand 4x4 is independently driven wheels at all corners, or some kind of fixed center diff meaning there's equal power to each wheel all the time.

AWD functions similar to an open diff in that the rear wheels engage when there's slippage/unequal load.

That's just what I've kind of picked up/figured out so I may be wrong though.

[Phi]

You're getting warmer Brink I forgot to metnion...the truck I'm looking at is Auto.

All-wheel Drive (AWD). An all-wheel-drive (AWD) vehicle has a driveline with the capability to send power to all four wheels, usually on a full-time basis. Most AWD vehicles are designed for all-season, instead of all-terrain, operation: ground clearance is usually closer to that of a car than a 4x4 truck, and the single-speed transfer case lacks a low-range. All-wheel-drive trucks currently on the market include the Oldsmobile Bravada, Toyota RAV-4 and Mercury Mountaineer. Also see Four-Wheel Drive.

Four-Wheel Drive (4WD). A vehicle with four-wheel drive (4WD) has a driveline with the capability to send power to all four wheels. Typically, the vehicle is designed for off-road, rough-terrain operation. The transfer case will include a low-range mode, and the vehicle will have more ground clearance than a typical passenger vehicle.

Full-Time 4WD. A full time 4WD system provides engine power to both the front and rear axles on all surfaces at all times. This usually requires a transfer case with a center differential, a viscous coupling, or both. Full-time 4WD improves traction and handling on paved surfaces in inclement weather, but may reduce fuel economy. Some model vehicles that offer full-time four-wheel drive: Range Rover, Land Rover Defender, Toyota Land Cruiser, Jeep Grand Cherokee, Mitsubishi Montero, Land Rover Discovery, and Ford Explorer.

Part-Time 4WD: Currently the least expensive and most common 4WD system. A part-time 4WD system is designed to be operated only on reduced-traction surfaces. The transfer case lacks any mechanism to allow front-to-rear axle speed differentiation. Thus, any accumulated driveline bind must be released via tire scrub. Extended use of part-time 4WD on a high-traction surface, such as dry pavement, can adversely affect handling and damage the driveline. Some, but not all, part-time 4WD systems allow the operator to shift from two- to four-wheel drive "on-the fly."

Shift-on-the-Fly. A vehicle with a four-wheel drive system designed to shift between two- and four-wheel drive while moving is said to have a shift-on-the-fly system. Current part-time shift-on-the-fly 4WD systems include GM's Insta-Trac, Jeep's Command-Trac, and Toyota's 4WDemand.

Source: http://www.tacomaterritory.com/~faqs...ll-wheel_drive

Okay..so based on the defn. above, AWD and 4WD are the same. the only think that may be different is the F/T and P/T aspect aswell as the capability to shift-on-the-fly (ie. Ltd Edition) right?

[JeremyH]

Originally posted by Phi
Okay..so based on the defn. above, AWD and 4WD are the same. the only think that may be different is the F/T and P/T aspect aswell as the capability to shift-on-the-fly (ie. Ltd Edition) right?

This is the difference......correct. AWD is 4wd, all the time.....4wd=4x4= selectable 4wd.

[Tex97]

My friend's dad just picked up an '03 Tundra V8 Access Cab SR5 with all the options. Wow! That is one nice truck. He tows a 2500 pound bass boat with no problems. I bet you'll find the Tundra to be a good truck for driving around the city.

I was all set as getting a Tundra as my next vehicle, but with the Titan now here I'll have to give it some thought. Oh well, I got a few years before I can get anything anyways

[TechJockey]

For traction in the snow/ice -

We just purchased an 04 4Runner limited V8 while trading a 97 4Runner SR5 4WD V6 . I am sure some of the updated engineering/increased size has some to do with the improved traction, but there is no comparison between these two cars on the snow. The 04 AWD is literally point and shoot while the 97 was good but not nearly as confident.

Also the SR5 has part time 4WD with locked differentials, which can make navigating turns much more difficult. You also can't really use part time 4WD in conditions that have some dry areas because turning can be so difficult and hard on the car. Ironically it is these changing conditions that are the most dangerous. IE you are driving up to a ski area and you are not sure where the snow will start.

Hope this helps.

[Rycam]

Generally, AWD is used in passenger cars, and various 4x4 systems are for trucks. AWD systems are lighter, less durable, smaller. They are perfectly suited to a car.

The term 4x4 is generic for a truck based vehicle that has four driven wheels at least some of the time.

Full time 4x4 is like heavy duty AWD.

Part time 4x4 was listed as the least "expensive", but is the strongest generally.

Shift on the fly is a convenient part-time 4x4, but lacks the overall strength of part time 4x4.

[ricqik]

to all these 4whatever terms. They all accomplish the same thing, that is to get power to all 4 wheels. It's kinda like trying to differentiate motors like, inlines, V's, W's, horizontal's and rotories. Each does it differently and better in some situations than others.

Personnally for city use I go awd and for work towing I like par-time. There's really just 3 types of 4 wheel drive systems. Part-time, fulltime and awd. Just that manufactures add little improvements to this and that to make it sound like their system really is new and different. In the end it still comes down to power to fr and rear tires.

Shift on the fly isn't even a 4wd system, it's just a push button or switch knob convinience feature. Again this fall into the "manufactures add this and that" sales pitch as stated above.

[crazycruzer]

4x4 spins all wheels at the same speed (even in turns), while AWD will adjust the speed of each front wheel when not in a straight line.

[virtualkuz]

Originally Posted by crazycruzer

4x4 spins all wheels at the same speed (even in turns), while AWD will adjust the speed of each front wheel when not in a straight line.

that is only if you have 3 locking differentials. Locking front, rear, and center. Trucks that have all that are pretty beefy. If you lock all 3 you are talkinga bout going a max of like 10mph over HEAVY terrain. you could never drive on a road with everything locked, the car would only go in a straight line. usually it will be some kind of limited slip situation, the wheels have to be able to turn at different speeds for cornering.

[ttownjoeshow]

Question......hey i am wunderin what 2X4 is...is it where you only have 1 tire in front and one in back with power???
thanks!!

[virtualkuz]

it is generally referred to as 4x2, and that is your regular old standard rear wheel drive.

[Bakemono]

Most 4x4s arent really 4-wheel drive. They typically have a limited-slip in the rear but only 1 front tire usually gets power (the Nissan Titan is the only truck that I know of to have a limited-slip front diff).
The difference from 4x4 to AWD is that AWD can sense how much grip each tire has and give the majority of the power to the tires that have the most grip.'
However, AWD typically results in decreased fuel economy.
Cap'n

[Rycam]

All this 4x4 talk is just that. Talk. As fun and informative as it is, talking about 4x4 this or AWD that does nothing for anyone. Talking and experiencing are two different things. No amount of "lab" can equal the experience! One can read all they want of about making "sweet looove" , but doing it is REAL!

Get out there. ride/drive as many 4x4's as possible. Get stuck. Get unstuck!