[Code of Federal Regulations] [Title 40, Volume 22] [Revised as of July 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR205.55-3] [Page 117] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 205--TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS--Table of Contents Subpart B--Medium and Heavy Trucks Sec. 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. (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 Sec. 205.55-2.