Is it worth taking a chance on using the Bias(D) rather than Radial(R) to save $80 on a set of 4 tires? I don't haul dirt or mulch on this trailer simply a couple riding mowers. And I don't run up the interstates only around town. My experiece is these radial tries don't last 2 years and the tread is worn down on one side. So why not get the Bias tires? Texas has suddenly gone to an insprection required on some trailers. And of couse my tires with plugs don't pass and neither do the tires with no thread on one side. And I can buy the whole darn tire and rim from Southwest for $86 apiece and that is $40 less than a tire from Discount. These tires guys now add on about $30 for rotation, tire disposal, warranty on sidewall, etc etc etc oh and mounting.