N.H. Rev. Stat. § 259:59
"Motor truck" shall mean any truck of greater than 26,000 pounds manufacturer's gross vehicle weight rating, or any motor vehicle equipped with other than pneumatic tires. The commissioner of safety may adopt rules under RSA 541-A to alter this weight limit to conform with federal statutes or regulations, provided that the limit does not exceed 26,000 pounds.
RSA 259:59
1905, 86:1. 1911, 133:1. 1913, 81:1. 1915, 129:1. 1917, 229:1. 1919, 161:1. 1921, 119:1. 1923, 75:1. 1925, 25:1; 68:1. PL 99 :1. 1927, 52:1. 1929, 43:1. 1935, 73:2, 3. 1939, 47:1; 130:1; 189:1, 2, 3, 5; 190:1. 1941, 98:1; 111:1; 142:2. RL 115:1. 1943, 189:1. 1947, 177:1. 1949, 189:1, 2; 197:1; 212:2; 233:1; 286:4. 1953, 252:3. RSA 259:1, XVI . 1967, 341:2. 1981, 146:1. 1985, 213:1. 1987, 404:16, eff. July 25, 1987.