The difference between four-wheel-drive and all-wheel-drive

[TopAuto]

The difference between four-wheel-drive and all-wheel-drive

All-wheel-drive and four-wheel-drive may sound like the same thing, but there are key differences that set them apart.

 

[Sinbad]

Lol the subaru Awd is a symmetrical AWD system that sends equal power to all 4 wheels by default. So more like your idea of a 4wd...

 

[prod]

Lol the subaru Awd is a symmetrical AWD system that sends equal power to all 4 wheels by default. So more like your idea of a 4wd...

Huh? Don't all AWD do that (Duster etc.)? I've always understood it as 4wd = transfer case and needs to be manually engaged, AWD = center differential and happens automatically

 

[Sinbad]

Huh? Don't all AWD do that (Duster etc.)? I've always understood it as 4wd = transfer case and needs to be manually engaged, AWD = center differential and happens automatically

Not according to the article

 

[RudderVator]

Huh? Don't all AWD do that (Duster etc.)? I've always understood it as 4wd = transfer case and needs to be manually engaged, AWD = center differential and happens automatically

They cant all be “symmetrical” AWD because the engine and gearbox are not symmetrical in distance from each wheel corner.

The main difference between AWD and 4WD is the fact that 4WD is only used in certain instances and never permanently engaged as you would wreck your diff on a tar road having it in 4WD mode because the inside wheels and outside wheels spin at different speeds around a corner and the system cannot handle that.

Subaru AWD for example would be an exception to that rule it has permanent 60/40 power split and can then move more power around to each wheel as and when it is needed if the car slips or goes around a tight corner to improve cornering performance.

The main issue other cars have with Transversal engine designs would be poorer weight distribution and torque steer because the engine and gearbox are all in the nose area instead of being spread out.

-With the a longitudinal layout such with a V8 one would need extra shafts to move to the front wheels from a transfer case. Extra shafts means extra weight and driveline losses and friction.