Polymeric gasoline deposit control (DC) additives have increased in acceptance during the 1970's. Their effectiveness in controlling gasoline engine carburetor and induction system deposits has been clearly demonstrated. However, with increasing use of unleaded gasolines, two side effects--increased combustion chamber deposits which can lead to increased octane requirements and increased oil viscosity due to migration of the additive package into the crankcase--have been noted.A new generation of DC additive technology based on a unique polyether structure was developed to minimize the noted side effects while maintaining deposit control performance. Extensive field tests of the new additive have demonstrated excellent deposit control with attendant maintenance of fuel metering and exhaust emissions performance. Vehicles using the new additive have octane requirements measurably lower than vehicles using the earlier additives.