What does "4 x 4" actually mean?


#1

I saw this Jeep today, a big “4 x 4” written in large letters on the back. So I got to wondering, why not just say 4WD for four wheel drive? Presumably one of the 4’s mean it is 4WD, but what’s the purpose of the other “4”? I mean, think about it, no secret it has 4 wheels like any other passenger vehicle, right? So why the other 4?

Then I got to thinking "Well, maybe 4 x 4 is a term that differentiates this type of four wheel drive system from other types such as AWD or all wheel drive. 4 x 4 means maybe means it has a transfer case, so the driver can switch between 4WD and 2WD at will. Maybe it means it has locking hubs. Vs. AWD which is always in some version of 4 wheel drive.

Any ideas, or is 4 x 4 just a marketing term and has no meaning beyond four wheel drive?


#2

The term 4 X 4 simply means that the vehicle has 4 wheels and all 4 of them are powered by the drivetrain.
Some pickups have been referred to in the past (although that marketing term seems to have died) as 4 X 2s; meaning 4 wheels with only 2 of them being powered and the other 2 just tagging along for the ride.


#3

Four total wheels; four driven wheels. A 2wd car is a 4X2…I guess a dually pickup would be a 6X6, or a 6X4


#4

Its a military term, mostly Army. Vehicles are identified by the total number of wheels and the number of wheels getting power. A regular car would be a 4x2. Larger vehicles can be 6x4, etc.


#5

A 6x6:

A “dually” counts as one wheel.


#6

Ah, that sort of makes sense, military terminology. Lots of Jeeps in the military, and – unlike the civilian life of the soccer mom and dad – lots of vehicles with more than 4 wheels in the military to deal with, so that terminology is a shortcut to describe the types of vehicles. Makes sense.

Terminology is important in the military I guess. I was dating a very nice military-enlisted lady quite a few years back, and one day she & I were going to meet up at a restaurant. She lived on base, and phoned up saying "George, I’m going to be late, I forgot I have to “de-weed” the back yard today.


#7

None of you guys are entirely correct :tongue:

The first number is the total number of wheels . . . or SETS of wheel in the case of dual wheels

A dually pickup truck . . . for example, a crewcab F350 dually . . . would still be 4x4

A 3 axle class 8 tractor where both of the tandem rear axles are driven would be 6x4 . . . 6 SETS of wheels, but only 4 SETS of wheels are driven


#8

Ooh that would be fun to have. Never really heard the 6x6, just mostly deuce and a half which I guess was 2 1/2 ton. Certainly no air suspension though. Hard as rocks to ride in.


#9

^If I had to pick one surplus vehicle as a toy, I’d probably want a GAMA goat.


#10

I always thought 4x4 meant 4 powered wheels and a four speed (manual) transmission.(as opposed to a 3 speed). I could be wrong, but that is my memory.


#11

^
No, that is not correct.


#12
^If I had to pick one surplus vehicle as a toy, I'd probably want a GAMA goat.

That is by far one of these most dangerous vehicles ever built. Very easy to flip. You turn right by locking the right wheels as the left wheels continue to turn…and visa-versa to turn left.


#13

When I was a young man 4X4 meant 4WD, 4 speed transmission. The meaning has morphed over the years to be used for any 4WD vehicle.


#14

TSM: I agree. I suspect that when 5 speed transmissions became common, someone had to find a new meaning for the other “4”.


#15

Bill, you’re probably right. The meanings of lots and lots of terms have changed in my lifetime. This is just one of many.


#16

Never heard of either ‘4’ referring to transmission speeds. Always number of wheels X number driven.

Now ‘442’ is another matter…


#17

marketing has muddied the waters regarding 4 wheel drive equipped vehicles. To the me terms mean
4 X 4 – is a vehicle with 4 wheel drive that is activated via a transfer case where the driver selects from 2 wheel drive (rear wheels), 4 wheel drive high range, and 4 wheel drive low range. This system has been used in domestic pickup trucks and SUV’s for many years.

4WD – is a 4 wheel drive that can be full time or part time depending on the system used by the manufacturer. These are often front wheel drive vehicle that add components to send power to the rear wheels. Often the selectors for these units are buttons, rather than a gear selector connected mechanically to the transfer case.

AWD – this is full time power to all 4 wheels where the driver does not select anything. Sensors and components monitor wheel spin and react according to the programming specified by the manufacturer in providing power to the wheels. Some systems use a viscous coupler transfer case and others are electronically controlled. These systems are used in Subaru, and Audi cars as well as modern pickups, crossovers, and SUV’s,

There are now so many systems in use that it is hard to really know is going on with any particular car until you study it’s particular system.

So, 4 X 4 has come to mean that the vehicle sends power to 4 wheels and it has become a generic term that applies to all the 4 wheel drive systems out there.


#18

In many companies the people in the marketing department are paid a great deal more than those in the design and manufacturing departments.


#19

I think I would have to agree with DB on this one. It definitely stemmed from military designations but I wasn’t aware of the “sets of wheels” idea. I guess that makes sense. I always thought it was number of wheels total…and number that are driven as well…like many others.


#20

The growth of terms is to try to describe what’s happening. 4WD means there is no center differential or device to disconnect the front or rear axle. No center diff means at least 2 wheels will spin in the mud. If you have a limited slip rear differential, 3 wheels spin in the mud. A front limited slip differential along with all that means all 4 wheels spin in the mud.

AWD means a 4 wheels can propel the vehicle all the time. That means you must have a center differential or some disconnect device so the driveline doesn’t bind. You can have part-time AWD, 2WD or 4WD in the same vehicle with some systems. Many SUV’s have a pushbutton selector for all the previous modes plus 4WD-low. Some still have a mechanical lever for 2WD, 4WD or 4WD-low.

Audi’s original Quattro system used a gear-type (Torsen) limited slip diff in the center and the rear with conventional diff in front. Rally racers added a Torsen in the front, too, for awesome traction. Later models dropped the center Torsen and went with an electronically controlled diff allowing torque to be commanded front or back depending on conditions.

AMC’s AWD system used a viscous center diff on the AMC Eagle car.