It took a better part of the weekend but Cindy and I were eager to get our new 40″ Cooper Discoverer STT Pro Tires mounted on our ATX Chamber Pro II bead lock wheels and installed on Moby as soon as we could and man, do they ever look GREAT! Click on the link below to see more photos of them installed:
For those of you who are interested, installed, aired up to 30 psi and with the full weight of our Jeep on the tires, the Cooper STT Pros measured 38-7/16″ to the edge of the tread and that puts them at almost an inch taller than our old Toyo M/T’s which came in at 37-1/2″.
Also, for those of you who were wanting to know, the weight difference is between a 40×13.50/R17 Cooper STT Pro and Toyo Open Country M/T, is about 15 lbs. Both mounted on an ATX Chamber Pro II bead lock wheel, the Cooper weighed in at 134.8 lbs. and the Toyo weighed in at 150 lbs.
Without having these tires balanced, we took Moby for a test drive and and found them to ride surprisingly clean and without any issues up to about 70 MPH. At 70, the front end stayed clean but we could feel some shimming in the rear end indicating one or maybe both tires were a tad out of balance. The shimming faded substantially at about 80 MPH. Needless to say, we’ll be getting them balanced soon.
Because of the large lugs and voids that mud terrains have, they ALL sing louder on pavement than an all terrain or street tire and of all the ones we’ve tested to date, we have found Cooper STT Pros to be slightly louder than something like a new Toyo M/T. That being said, our old Toyos had about 17,000 miles on them and were actually louder on pavement than our new Coopers. Of course, compared to our old Nitto Mud Grapplers, these Coopers are essentially silent.