I'll chime back in here....

In my actual road test during the snowstorm I found:

1. You can skid ABS. They don't guarantee tires rolling to a stop on snow, ice, etc.

2. IMHO, skiding the front tires is what we are calling "locking up".

3. Stopping distance most likely did increase with ABS wheel lock up.

4, I did not test this condition and try to steer as the same time. It would be interesting to see a study which tests steeeing ability of ABS with wheel lock up vs. conventional brakes, also locked up.


5. When the wheels did lock up and/or slide on snow, the car also steered to on side (right, in my Coutour's case). The off-line tracking was a LOT LESS then I experience with conventional braking (locked up, without pumping)

6. While sliding, the rear end did not tend to "come around" on me. I think conventional braking tends to let this happen more than ABS.

7. I achieved maximum steering control (not necessarily stopping success) when I "finessed" the brake pedal a little bit. That is, when I felt the tires sliding, I backed off the pedal some. This seemed to allow the tires to roll again and give ABS a chance to "try again"

8. It is only common sense that one should "start braking early" and allow this gradual approach to life give maximum control. My original question stemmed from my intentional hard braking, which I was doing to gain the feel of ABS. So, what I was doing was creating "panic stop" situations to dissover what I could expect. I also make it a habit, when it is safe to do so (no cars nearby, nothing to slide into, etc.) to do one or two hard braking attempts to test road surface conditions whenever I enter a new roadway (such as entering the freeway, or after a merge to a new section).

My conclusions about ABS:

Same or better straight stopping distance if tires do not slide.

Don't assume shorter straight stoppping distance compared with conventional brakes if tires slide.

ABS seems to offer more steering control and/or regain steering control better/sooner than conventional. So, yeah, maybe you'll have the opportunity to steer around something instead of sliding straight into it. ABS also seems to minimize the rear end "coming around" on you and sending the car sideways.
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1989 740Ti 1986 240DL 1984 244GL