Tire Friction Comparison of Three Tire Types 2013-01-0783
The purpose of this paper is to demonstrate the differences in braking capability of the different types of tires through data collected from single variable testing. The only variable in these tests was the type of tire installed. Three different tire types; summer, all season, and winter, all of the same size, were tested in moderate ambient temperature on wet and dry asphalt surface with a single vehicle. The braking tests were conducted with ABS actived and deactivated for modulated and locked wheel friction comparison of the tire types.
Accident reconstructionists rely on accurate friction coefficients to calculate speeds from skid and yaw marks left at a collision scene. Maximum effort braking performance, whether locked wheel or ABS modulated, is influenced mainly by the road to tire interaction and is affected by the type of tire.
High performance, “Summer”, tires are increasingly available as Original Equipment Manufacturer fitment. These tires were once reserved for sports cars and European performance sedans. Today they are available as standard or optional equipment on domestic Sport Utility Vehicles and compact cars. Summer tires are not intended to be used when temperatures are near freezing or on snow and ice, necessitating the use of either all-season or winter tires for owners in areas that are susceptible to these roadway conditions.
The vehicle chosen for this testing is available from the manufacturer with either all-season or summer tires. The vehicle was left in an as manufactured condition for all tests, with the exception of tire changes and deactivating the Anti-Lock Brake System/Electronic Stability Control Electro-Hydraulic Control Unit for locked wheel tests. The vehicle was braked from a target speed of 45 MPH for all tests. A total of 72 tests were conducted on both wet and dry pavement conditions.
The results show differences not only between the tire types, but how each tire types' friction varies between wet and dry asphalt and ABS modulated and locked wheel braking. The results report tire friction values higher than typically published numbers.