205.55-3—Configuration identification.
(a)
A separate vehicle configuration shall be determined by each combination of the following parameters:
(1) Exhaust system configuration.
(i)
Single vertical.
(2)
Air induction system (engine ). (i) Natural.
(a) Direct.
(b) Thermostatic.
(4) Engine manufacturer's horsepower rating.
(5) Cab characteristic.
(i)
Sleeper.
(6) Category parameters listed in