I agree with TobyS, stay with duals, more stable. Also, with duals you can have one tire fail and still limp along to get home or to help. Blow a big single and you are stopped. I often think of that when I see semi's with the new super wide singles. I automatically think "Buddy, blow or puncture one of them and you are done!". Instant expensive road service call! One fuel distribution business here tried them on tanker semi's and soon quit, back to duals, for that reason. Also, so aggravating to me, new tires must not have much if any honest rubber in them. A few years and cracks start to appear. I have not had any new truck tires, but I see it with aggravating regularity on car and pickup tires anymore. Our old trucks, including the dump, have the older military tires on them and none of this to me premature cracking is happening on them and some are dated in the '70's. I have never had one of them fail in what I could attribute to their old age, we just wear the tread off them. I have a homemade welder trailer with a tire on it that was on a farm wagon Dad bought when I was about 10, it is now about 60 years old, still going without the cracking and failures that have happened to newer used tires on the other side of the axle. I think tire companies are doing like other product designers nowadays, design it to last only so long. "Let's see the engineer says, a driver normally wears out a tire in x miles and say three years, so why design it to last longer than that?" Also, true rubber tires would probably be very expensive if even possible to make now. Many times it sucks to be an old guy that knows how good products used to be made and has to live with what we get nowadays.