Configuration identification.

(a) A separate vehicle configuration shall be determined by each combination of the following parameters: (1) Exhaust system configuration. (i) Single vertical. (ii) Dual vertical. (iii) Single horizontal. (iv) Dual horizontal. (2) Air induction system ( engine ). (i) Natural. (ii) Turbocharged. (3) Fan. (i) Diameter. (ii) Drive. ( a ) Direct. ( b ) Thermostatic. (iii) Max fan rpm. (4) Engine manufacturer's horsepower rating. (5) Cab characteristic. (i) Sleeper. (ii) Non sleeper. (6) Category parameters listed in § 205.55-2.