N.J. Stat. Ann. § 39:3-22a

If application is made for the registration of a motor vehicle, other than a passenger automobile or motorcycle, or for the registration of a commercial motor or motor-drawn vehicle, or an omnibus, on or after October 1 in a registration year beginning April 1 and ending the following March 31, the applicant shall pay only one-half of the registration fee provided for in the class to which such vehicle belongs.