N.H. Rev. Stat. Ann. § 339-C:8
Any of the following provisions in an agreement or lease, if one is included, whether oral or written, between a supplier and dealer, shall be void as against public policy:
III. Provisions requiring a dealer to purchase any products of the supplier other than gasoline or diesel fuel. The dealer may, however, agree to accept such products on consignment, but not exclusive as to like products; or
III-a. Provisions restricting a dealer from reusing motor oil or waste oil for heating purposes; or
Source. 1974, 24:1. 1990, 88:1, eff. June 9, 1990.