Re: Motorweek shortchanges AMC

[Rhett Butler <amc.inline.six@xxxxxxxxx>]

I Googled it. I knew there was more of a difference than just wet/dry driving ability.

ALL WHEEL DRIVE:

Definition: A vehicle where all four wheels are driven, but there's no transfer case like a four-wheel drive rig. Most AWD setups are full time systems for year-round driving, and use a viscous fluid coupling center differential instead of a transfer case to route drive torque to all four wheels. This allows the front and rear wheels to turn at slightly different speeds when turning on dry pavement. Most folks do not consider this the same as four-wheel drive. It can be useful (and more fuel economical) in pavement driving where you're mainly negotiating bad weather conditions.

FOUR WHEEL DRIVE

			Definition:
A method of driving a vehicle by applying engine torque to all four
wheels thru the use of a transfer case, differentials and hubs. Various
schemes are used for 4WD including part-time, full-time and variable
four-wheel drive. To help cut the drive train drag (and reduced fuel
economy) that most 4WD's have, a transfer case is included that allows
the driver to select either two- or four-wheel drive depending on
driving conditions. Some performance cars have full-time variable
four-wheel drive and use a computer-controlled transfer case to route
power between the wheels.

It would appear that in this case, the Eagle was 4WD...at first, it was full-time. From mid-1981 on, it was part-time, with shift-on-the-fly capability coming in '85, and of course, the whole time, it was able to be employed on wet or dry road surfaces.

On 12/11/05, Sandwich Maker <adh@xxxxxxxxxxxxxxxxx> wrote:

" From: Roger Blake <rogblake@xxxxxxxxx>
"
" Rhett Butler wrote:
" > And technically, I suppose, the Eagle was never available with AWD. The
" > Eagle came with 4WD.
"
" As I understand it, the difference between "4WD" and "AWD" is that
" the former cannot be used on dry pavement due to the lack of a center
" differential, and therefore are part-time systems. (This is the case
" with the early Subarus as well as the old Jeep 4WD wagons of the late
" 1940s.)

getting technical again, i'd class awd as a subset of 4wd, since in
both cases all 4 wheels are powered.  '4wd classic' is as you say.

" Since all AMC Eagles have a center differential and can be left in
" "4-wheel-drive" under all conditions, including on dry pavement, they
" actually should be classified as "all-wheel-drive" vehicles.

and they weren't, because 'awd' hadn't yet been coined.

" Of course things get even more confused since AMC themselves used the
" terms "Automatic 4-wheel drive," "4-wheel-drive," and "Select Drive" to
" describe the Eagle's capabilitites.

i've also heard 'fulltime 4wd' for similar systems of the era.
________________________________________________________________________
Andrew Hay                                  the genius nature
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