Full Time Vs. Part Time AWD ?

Yeppers. Lever, button, whatever. You have to intentionally activate it.

Patty

I remember the days with a friend's truck where you had to get out and turn the hubs in the front wheels.

First Subaru I drove but did not buy, you had to push a button.

part-time AWD ?

My outback is part time. I would rather have a switch or lever.

Greg

Frank:

My 1991 Toyota 4WD pickup truck, e.g.

I would consider the system in most "crossovers" and the new forester (save for manual base trim) part time since most of the time power is send to one axle. And on majority of cars that's the wrong axle overloaded with work already (braking and turning).

How it works varies. Old school approach was a mechanical diff or two, newer system are electronically actuated.

Full time systems send power to both axles most of the time, hence there is a lot of flexibility to address driveability (squelch understeer) and avoid getting stuck on ice, in snow/mud

part time systems, either lever actuated or electronically actuated are the johnny come late kind of deal but have the advantage of saving a quarter pint of gas per 100 miles

In the olden days, yes, you had to flip a switch or lever, etc. Nowadays, the computer determines if it detects wheel slippage and turns on the 4WD system as needed automatically, no need for you to flip or push anything. This I would call automatic part-time 4WD. The power is not going to all wheels all of the time.

In full-time 4WD, the power is always going to all wheels, at various levels of power distribution.

Most other SUV's, other than Subarus have this automatic part-time AWD systems.

Watch these videos:

Yousuf Khan

Right. You will have to push the car though when you overheat that electronically controlled clutchpack offroad

I finally get it. Rogue means that the car will have a brain of it's own through the apex and Escape means that you have the car that can escape the apex altogether. Tongue is firmly in the chick.

Another thing I noticed is that for any models that offer AWD as an

*option*, will most likely have a part-time AWD system, and usually a crappy one at that. So if you get a car offered mainly as a FWD (and more rarely as a RWD), and optionally with AWD, you can be sure that the AWD was an afterthought. You're better off to choose the FWD version, as the AWD will help you nada. Most of the time the AWD won't even kick in at all when you need it! It just gives you a false sense of security, thinking you might have AWD, when you really got nothing.

Check out this very misleading video put out by a paid test group to make the Toyota Venza's AWD look decent:

Notice that they felt they had to put their car up against an Outback? The test may seem rigorous and "real world", but an ice-skating rink is not real world at all. It's basically testing glare ice conditions, where pretty much all cars have equal traction, i.e. extremely low but not zero, whether it's AWD, FWD, or RWD. Hell, you can have Ford Mustang drive around a skating rink, as long as you go slow enough not to break traction; and a Mustang is one of the most dangerous cars in the winter. Once you've broken traction, every car will go sliding. Mind you, it's possible with a full-time AWD to find the little hint of traction, since you have 4 wheels working to find it. A much better real-world test would be to have glare ice on a lane change or a slalom, and see how they fare.

The real story is here in this video:

Though rollers don't seem like real-world, what they are actually testing here is icy conditions on an uphill section. If a car can't get itself up over even a slight incline, then it's useless. Even plowing through a snow-bank is part of this skillset, because snowbanks involve the car undulating up and over alternating hard-packed snow and soft-packed snow, which is like doing many thousands of hillclimbs.

Yousuf Khan

bwahaha, they came stock with all season tires and I bet two different models since venza uses 50 to 55 profile depending on the model while outback sidewall is likely taller

What a bunch of idiots. Put identical snow tires on and then maybe there will be some credibility

it's fine, you just have to come out and push it a little every now and then, should not be an unfamiliar pastime for people who are switching one $30k+ door stop to another