Terminology

[EMB1230]

Do you say RWD or 2WD? I said 2WD to my mom one day and she didn't know what I was talking about, lol. I know that the correct term is RWD, and the layman's term is 2WD, but what do most people actually say?

 

[02RangerXLT]

2WD is what I call vehicles that had the option of 4WD from the factory but didn't get it.

Ex:

Ford Ranger = 2WD
Ford F350 = 2WD

Ford Crown Victoria- RWD
Ford Mustang- RWD

 

[LearjetMinako]

2WD, 4WD, AWD, 4x2, 4x4, part-time, full-time, real-time, FWD, RWD. Does it really matter what it is. 2WD just means two wheels are the driving force. FWD or RWD most likely means its 2WD, just now its indicating which wheels pull the driving force. For me, if it is 2WD vehicle, I will usually say its either RWD or FWD. For 4WD, doesn't matter, it is either RWD or 4x4. For all wheel drives like the Subura's, who cares. It is all wheel drive, all the time, so it is ready for fun time.

 

[adsm08]

In terms of a Ranger, either is correct.

Rear wheel drive is a vehicle that is driven solely by the rear wheels.

Two wheel drive is a vehicle that has a drive train that powers only 2 of the wheels.

Rear wheel drive is pretty specific, but two wheel drive can be applied equally correctly to any purely RWD of FWD vehicle that has neither a 4x4 or all wheel drive system.

 

[shane96ranger]

I think in years past 2wd meant as stated above, a vehicle that had 4wd available, but does not get the option. Now there are some newer vehicles that don't receive the 4wd option that are front wheel drive, like my Ford Escape. I think this is where people are starting to define it deeper than just 2wd because generally an SUV is a rear wheel drive vehicle.

I understand it either way, and I'm sure most people on here do.

 

[RustedRanger]

With trucks I say 2WD or 4WD,cars either RWD, FWD....or AWD. Its funny that on the show Top Gear that most times they call a car with AWD ,4 wheel drive. I still don't like hearing wheels called "rims"....same thing really except to me a rim is the outside of a wheel. I guess a lot of is what things were called when we grew up.

 

[--weezl--]

what i find ironic is that most vehicles that we call 2wd, aren't actually 2wd being that they have open differentials... which makes them kinda 1 wheel drive... me, i'm glad i've got 3wd for off roading

subaru's are also 1 wheel drive, even though they are called all wheel drive, because they have 3 open diffs

 

[RatDog8o8]

I still don't like hearing wheels called "rims"....same thing really except to me a rim is the outside of a wheel. I guess a lot of is what things were called when we grew up.

I've seen it both ways - some call the combo of a rim and a tire the "wheel"; others say "wheel rims" while others go with the "wheel" being the part that the tire mounts to.

A similar issue is "motor" vs "engine". I was told once that a "motor" runs on electricity, while an "engine" refers to some sort of combustion-type powering unit.

 

[LearjetMinako]

what i find ironic is that most vehicles that we call 2wd, aren't actually 2wd being that they have open differentials... which makes them kinda 1 wheel drive... me, i'm glad i've got 3wd for off roading

subaru's are also 1 wheel drive, even though they are called all wheel drive, because they have 3 open diffs

An engineer point of view. I like that.

 

[--weezl--]

lol i love my 3wd truck! how about a 1 wheel drive vehicle leaving 4 black lines from all 4 tires? is it still 1 wheel drive or is it 4 wheel drive then? now we get into a bridge between physics and philosophy

I've seen it both ways - some call the combo of a rim and a tire the "wheel"; others say "wheel rims" while others go with the "wheel" being the part that the tire mounts to.

A similar issue is "motor" vs "engine". I was told once that a "motor" runs on electricity, while an "engine" refers to some sort of combustion-type powering unit.

engine is spesific to combustion engines, and i think specifically internal combustion engines, where as motor is a device that causes motion, an electric motor is a motor, an engine is a type of motor, there are also centrifugal motors... basically those little toy cars you push forward on the ground 3 or 4 times and it kinda winds up, then you put it down and the wheels are already turning, that's a weight set into a spinning motion and geared back to the wheels, the weight of the weight and the momentium keep it turning and propell the car forward, because it propells the car and causes motion, it's a motor electric drills have motors, vacuum cleaners have motors "motor" is a very generic term

 

[gribly]

God, not this again. A vehicle with an open differential is in no way shape or form 1wd. There is no such thing. With an open differential, for just one tire to spin, it has to have less than half the traction of the other one. My Navajo has open differentials but it lights up both rear tires when dumping the clutch and it walks right sideways when doing a brakestand. On a clutch drop, on my old michelins, I could get about 10 feet of rubber with the left tire and about 30 with the right, but I can only get the right tire to stay spinning in 2nd.

 

[--weezl--]

i can take a rwd car and leave 4 big black lines too... doesn't make it 4wd

the way an open differential works, it is really only 1 wheel drive, if it were 2 wheel drive, we wouldn't have the need for lockers... and actually, in many ways, an actual 1 wheel drive vehicle (one motor going to one wheel with no differential) would provide better traction in a lot of situations than a 2wd vehicle...

 

[5.0]

For 4WD, doesn't matter, it is either RWD or 4x4.

What about the 4x4 SUV and crossovers that are FWD, then the rear differential is engaged to make it a 4wd?


.

 

[gribly]

i can take a rwd car and leave 4 big black lines too... doesn't make it 4wd

the way an open differential works, it is really only 1 wheel drive, if it were 2 wheel drive, we wouldn't have the need for lockers... and actually, in many ways, an actual 1 wheel drive vehicle (one motor going to one wheel with no differential) would provide better traction in a lot of situations than a 2wd vehicle...

Take a vehicle with an open differential and jack it up in the air so that the tires spin freely. Now, with the driveshaft locked, spin one tire. Notice how the other tire spins the exact same speed in the opposite direction? Now, with both tires free, spin the driveshaft, and watch both tires spin. Now, take one of the tires and lock it, and spin the driveshaft again, the free tire will spin exactly twice as fast as before. Like I said before, this means you need twice as much traction on one tire compared to the other in order for only one tire to spin. Now, there is a difference between static and kinetic friction, meaning that if one tire starts to break loose first, it will just spin since the other tire still has static friction, which is much greater than kinetic friction. It's simple physics, a 2wd vehicle is a 2wd vehicle, there is no voodoo or magic that causes just one tire to spin, and it's not like the driveshaft is more directly connected to one tire than the other, in an open differential, no matter what, both tires will always receive the exact same amount of torque. With a locked or spooled diff, there is no diff movement, so the torque split between the tires is a direct ratio to the amount of traction each tire has.

And about the actual 1wd thing, like in a simple go-kart that only drives one tire - it really will have half traction of a 2wd with an open differential as long as you don't break loose with one tire - because of the static and kinetic friction difference. Now, with both different setups launching hard and spinning, the 1wd kart still will not have quite as much traction due to the open differential spinning the one tire twice as fast.

 

[--weezl--]

traction can only be measured at a threshold amounts... in other words, comparing traction when loss of traction is not a factor, means nothing, as traction at that point is infinite...

take a vehicle with say 100 hp, and an open diff, lift the back wheels off the ground and you hold on to one of those wheels, the other wheel left unrestricted, now apply all 100hp to the rear wheels at the same time, you're not going to have any problems holding onto that one wheel... because the vehicle is only driving 1 wheel at a time.. additionally to that, your 1/2 the traction statement is flawed, it won't cause one wheel to spin when 1/2 the traction is on one wheel as compared to the other, it is 1/2 of the total traction of both wheels, so if there is any difference in traction (above and beyond the threshold that the resistances in wheel bearings, differential bearings, and spider gears will cause) then one wheel is going to spin, if you have 1/3 of the total traction on one wheel and 2/3 on the other it will spin the one with 1/3, if you have 3/8ths the traction on one, and 5/8 on the other, the one with 3/8 will spin, only driving one wheel...

in actual practice an open differential only drives one wheel when it matters, and that's where loss of traction is at play, if there is no loss of traction you could have 8wheel drive, and you're not going to see any benefit