Super Singles

Groover wrote:
The resistance to super singles reminds me of how hard it was to get truckers away from cross bar tread for the drive tires back in the '70s. Those things were noisy and really hurt fuel economy but some drivers would not give them up. All the same, it happened eventually. We have all carried spare tires for years but a lot of new cars(and coaches) don't come with spares anymore. A big chunk of the reason for that is simply that tires don't fail nearly as often as they used to and we just don't need to carry spares. That same factor might encourage us to switch to super singles if we can convince ourselves that we can live without the redundancy that duals give us.

My understanding is that super singles have reduced rolling resistance mostly simply because they are only flexing half the number of sidewalls that duals have. I have heard savings estimates of 5 to 10 percent. I would take that. Another advantage is the weight savings. From what I hear you can resuce the weight of an 18 wheeling by 650 pounds with super singles. Due to only having one fourth the number of duals we could call that 162 pounds for most class A's. That could also aid fuel economy and improve ride by reducing unsprung weight or let you carry that much more. One thing that I have wondered about is that it appears to me that a super single is narrower than two regualar tires with the spacing between them and would allow the shocks and springs to be placed farther apart, that could improve handling.

Even though super singles seem to be fairly popular in my area I don't recall ever seeing one one the side of the road with a flat tire. Maybe reliability is not the issue that we assume it is. Regardless, I don't think that they make super singles to replace the pair on 255/75/22.5's in the back of my coach so I don't guess that I will be trying them anytime soon.