Time for new tires for my -4 (currently 5.00 x 5, 6 ply). I'm looking at the Goodyear Flight Custom III (160 mph) or the Flight Special II (120 mph). Is the speed rating the max landing speed? The Flight Special IIs are a lot cheaper but are the Flight Custom IIIs that much better? Are there any other suggestions for tires? Any brands to stay away from?