[Swampdude]

If you get a chance to watch the 2007 Einstien finals, you'll see our 6wd robot that is only driven on the rear 4 wheels playing defense quite nicely. And if you watch the Florida Regional finals of 2008 you'll see our 6wd robot with only the 2 center wheels driven do quite nicely as well. I think the key of 6wd is keeping the CG on those center wheels - or at least over the set of 4 that are driven. You also need to lower those center wheels at least 3/8". I think you should drive all 6 when you can't consistently balance the majority of your CG over the driven wheels. But if the bulk of your cg is consistently on your rear set of wheels, driving the front set won't help much. The magic of 6wd is only (1) of (2) sets of square wheel patterns on the floor at any time, vs a rectangular linear 4 wheel pattern adding drag during turns.