tires                 package:Simple                 R Documentation

_T_r_e_a_d_w_e_a_r, _T_r_a_c_t_i_o_n _a_n_d _T_e_m_p_e_r_a_t_u_r_e _R_e_s_i_s_t_a_n_c_e _o_f _p_o_p_u_l_a_r _t_i_r_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     The 'tires' data frame has 2164 rows and 7 columns.

     data set taken from
     http://www.nhtsa.dot.gov/cars/testing/tirerate/ which lists

     Treadwear (WEAR)

     The treadwear grade is a comparative rating based on the wear rate
     of the tire when tested under carefully controlled conditions. For
     example, a tire graded 200 should have its useful tread last twice
     as long as a tire graded 100. However, real world tire tread life,
     in miles, depends on the actual conditions of their use. Tire life
     is affected by variations in driving habits, service
     practices...such as tire rotation, wheel alignment and maintaining
     proper inflation pressure...and differences in road
     characteristics and climate.

     Traction (TRAC)

     Traction grades represent the tire's ability to stop on wet
     pavement as measured under controlled conditions on asphalt and
     concrete test surfaces. The traction grades from highest to
     lowest, are "AA", "A", "B" and "C". A tire graded "AA" may have
     relatively better traction performance than a tire graded "A", "B"
     or "C", based on straight ahead braking tests. The grades do not
     reflect the cornering or turning traction performance of the
     tires.

     Temperature Resistance (TEMP)

     Temperature grades represent the tire's resistance to heat and its
     ability to dissipate heat when tested under controlled laboratory
     test conditions. Sustained high temperature can cause the tire to
     degenerate and reduce tire life, and excessive temperature can
     lead to sudden tire failure. The temperature grades from highest
     to lowest are "A", "B" and "C". The grade "C" corresponds to the
     minimum performance required by federal safety standard. Grades
     "B" and "A" represent higher levels of performance than the
     minimum required by law. The temperature grade is for a tire that
     is inflated properly and not overloaded. Excessive speed,
     underinflation or excessive loading, either separately on in
     combination, can cause heat build-up and possible tire failure.

_U_s_a_g_e:

     data(tires)

_F_o_r_m_a_t:

     This data frame contains the following columns:

     _B_R_A_N_D A factor describing the brand

     _C_O_N_S_T a factor describing construction

     _T_I_R_E_L_I_N_E a factor describing the model line

     _S_I_Z_E a factor describing the size of the tire

     _T_R_A_C a factor describing traction

     _T_E_M_P a factor describing temperature

     _W_E_A_R a numeric vector describing wear characteristics

_S_o_u_r_c_e:

     http://www.nhtsa.dot.gov/cars/testing/tirerate/

_R_e_f_e_r_e_n_c_e_s:

     Prompted by the Firestone and Ford battle this dataset provides
     some look at tire factors.

_E_x_a_m_p_l_e_s:

     data(tires)
     attach(tires)
     plot(WEAR ~ TEMP)
     detach(tires)

