A method of producing lower emissions in the operation of a vehicle includes an internal combustion engine which gives off exhaust gases to an exhaust system comprising a catalytic converter, injectors which are designed to inject hydrocarbon into at least one of the exhaust system and the engine combustion chamber, and a transmission that can be driven by the engine. The method includes a step in which a gear in the vehicle transmission is selected as a function at least of information that catalytic conversion is required and information on the temperature in the exhaust system, so that the gear selected regulates the temperature in the exhaust system. The catalytic converter is preferably of the LNC (Lean NO, Catalyst) type.