On 5/5/2011 8:44 AM, Stormin Mormon wrote:
At 70 MPH, you'd have no reason to engage 4WD. You may be
grinding gears, there.

On my Chevrolet, 4WD is only used on sand, snow, and
surfaces which have some slip. My 1998 model is "engage on
the fly". My earlier 1989 model would only engage standing
still, with transmission in neutral.


Had to use the 4WD on my Chevy on the street a few months ago. Stop
light on a hill in the rain. Hadn't been raining long enough to wash
clean yet. I just sat there and spun the rear wheels until I kicked on
the 4wd. Thank goodness for push button shift on the fly 4wd.

Anyway, he is talking about an always on or full time 4wd. Dodge had
some trucks that were always on limited slip 4wd. Porsche makes some
always on AWD. I think all Subarus are always on AWD. Lots of other
mfgs do.

I don't know first hand, but I have heard that AWD tends to stay in
control better when you get a sudden unexpected surface change... Its
not a miracle cure, but if you aren't running on the ragged edge already
it can save your bacon on things like black ice.