pic: 4WD Concept

[IKE]

Originally Posted by JohnFogarty

I honestly don't know why this would occur. The turning scrub of this drive-train would be noticeably less than that of a 6WD.

...snip...

It would depend on the CG location. Let't take a couple of extremes and then this might make sense.
1. If the CG is really close to being over the top of the omin-end, then turning can be difficult as the traction wheels act a bit like a rudder.

2. If the CG is nearly directly over the top of the traction wheels, then there will be very little lateral from the omnis which can make it difficult to drive straight.

1 can be a very bothersome configuration as you would get pushed around easy without the benefits of being really maneuverable.

2 can be difficult to drive in a straight line, but should be very very maneuverable.

There is a white paper by Chris Hibner that you can use to set up a calculator and play around with values.