While there are often recommendations for tires that excel in bad weather conditions, there seem to be little information –if any — for tires that excel in drought conditions currently bedeviling a large part of the country, including Texas.
Most people think of drought driving simply as motoring on dry roads, but long periods without precipitation cause a build up of dust, oil and other things. The winds that often accompany drought can spread stuff that becomes nearly invisible when a drought is long lasting. These conditions can be of particular concern when towing, off-road, or when travelling on less-used roads and we wanted to know if certain tires are better than others for maintaining good performance.
I recently had a chance to speak with Mike Stoltz, Cooper Tire Product Segment Manager about this. The company maintains an impressive 1,000 acre tire and vehicle test center in Pearsall, Texas, about 40 miles from San Antonio, an area that has experienced drought conditions for the past two years. The center has four primary test areas — an oval for ride/traction/slalom; a dry handling circuit; wet vehicle dynamics area; and off-road test course. I’ve had the chance to drive them and can attest to both the challenge and the quality of the facility.
While it would seem that the 1.3-mile dry handling circuit with its low and high speed capabilities, the dry circle for measuring maximum dry lateral grip, 1,200-foot straightaway and three double lane changes. It is the wet vehicle dynamics assessment pad that is most effective, Stoltz suggests, that — though counter-intuitive — offers the best assessment for drought-driving performance.
“Dought conditions affect wet traction by changing the micro-texture of the road surface and through the accumulation of oil. The micro-texture of the road surface is polished by normal vehicle traffic, and rain helps to restore the micro-texture by etching the surface of the asphalt…also helps to wash away the accumulation of oil and dirt,” he explains.
Speaking of the Cooper wet track, a 16-acre by 16-acre area where water levels can be monitored for levels from 0-.15″, he continued, “We do not have the ability to test tires under these two conditions because we need to use the wet surface ever day and…keep the surface as consistent as possible for repeatability.”
The closest that Stoltz says that they can come to simulating the drought and rain aftermath is by testing on different test tracks with different coefficients of friction. They indicate that they have seen some subtle ranking differences between products tested on different surfaces, “however, the ordinary consumer would have a very difficult time seeing these differences.”
Cooper’s recommendations for replacement tires for these conditions are: