Posted by Alan Bowes on February 21, 1998 at 10:43:43:
In Reply to: Tire recommendations for M-37/WDX posted by rick on February 18, 1998 at 09:22:04:
A few thoughts:
Try to match the tire type for your driving environment.
Non-belted bias-ply tires are best for conforming to extremely rough, rocky terrain, especially with lower air pressure. These tires have the highest amount of rolling resistance and tread "squirm" so they are the worst on the highway and have the shortest tread life.
Belted bias-ply tires don't conform to rough terrain quite as well as non-belted bias-ply tires, but like a radial, they have less tread squirm, which improves tread life and makes them somewhat better than a non-belted tire in snow and harder muds. Compared to radials, the sidewalls are stiffer and may offer a little more protection against penetration from stones or branches.
Belted radial tires provide similar traction characteristics to the belted bias-ply tires, but have lower rolling resistance and less heat buildup, making them best for high-speed use. The sidewalls tend to me more vulnerable to penetration. With radials, the vehicle rests a little lower, due to the flexible sidewalls, giving the tires a "half-flat" look. One advantage to this, however, is a longer "footprint" with the resulting better traction (at least on some surfaces). To get this long of a footprint with a belted bias-ply tire, you'd have to let more air out, which would build up more heat, especially at higher speeds.
Military steel-belted radial tires often have extra steel plies in the sidewall for improved penetration protection. However, this makes the tires heavy and less suited for high-speed operation.
For general off-road use, I still like belted tires (either radial or bias), although if you happen to do a lot of slickrock/canyon country driving, where you often deal with big rocks, ledges, fissures, and other extremely rough terrain, and you don't mind airing your tires up and down as required (and driving very slowly over obstacles), then a non-belted bias-ply tire is the way to go.
By the way, Michelin military-type tires are available in 9.00R-16, but expect to pay between 375 and 450 dollars per tire.