Question about four-wheel steering.

[MrBond]

GMC offers Quadra-Steer on their big trucks, no review I've read mentions improved cornering, but apparently it makes parking manuevers much easier

 

[Evadman]

I have driven in vehicles with 4 wheel steering. Mostly trail vehicles, but I have driven the new GMC Denalli that has the 4 wheel steer.
It is a very weard feeling when driving. It feels like you are sliding sideways during low speed cornering. at high speeds, the rear wheels turn the same way as the front ( for instance, both to the left) This would not work at all for high speed cornering. even if you could get them pointed corectly, swinging the ass of a vehicle that far at high speeds is bad. Then the rear of the vehicle ends up with sideways kenetic energy which will aid in removing traction. In otherwords, the ass end will be swinging in the opposite direction then the front. This is bad! BAD! Then the ass wants so keep going, and you end up doing a nice sideways skid at high speeds.

If you ever get the chance, drive a 4 wheel steer vehicle. I drove one at a rock crawling competiotn ( not in the competion, mind you, but I was there and met a guy who let me drive his portal axle 4 wheel steer vehicle in the dirt ) It was quite a bit different as anythign else, as you could turn the rear wheels wherever you wanted with a toggle switch. the rear wheels went to almost 70 degrees. A really neat truck ( which he would not let me do, but he demonstrated ) was a 0 foot turning radius. He turned the fronts to the right, the rears to the left, and locked the inside rear wheel with a handbrake. ( he had 2, one for each wheel ) and disengaged the rear air locker. Then stomped on the gas. That buggy spum around on that rear tire.

sorry, I digress. Here, in just a few words: 4 wheel steer is for TOWING and LARGE VEHICLES. Not performance cars.

 

[flot]

Which, of course, is why Nissan put 4 wheel steering on the 300ZX, the Skyline, and certain (rare?) 240sxes.

4 Wheel steering in my 300ZX is not weird at all. It is there, and I would probably notice if you took it away, but the car behaves predictably and normally. Again, it only moves a few degrees max. It couldn't possibly help in any kind of parking maneuver.

Of course, different systems are designed different ways. But overall, I'd say 4 wheel steering would be a good technology for any car, implemented appropriately for the need.