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General Motors has introduced a new front wheel drive seven speed dry dual clutch automatic transmission in 2014. The 250 Nm input torque rated gear box was designed and engineered for a global market in both front wheel drive and all-wheel drive configurations. The transmission has integrated start/stop capability enabled by the use of an electric motor driven pump and a pressurized accumulator. The architecture selected was chosen for optimization of packaging, fuel economy, mass, shift pleasability, and NVH. High mileage durability and world class drivability were the cornerstone deliverables during the engineering and design process Fuel efficiency is estimated to be 3% - 10% improvement over a conventional six speed automatic transmission. FWD variant wet mass of 78.1 kg was achieved through the rigorous engineering processes used to optimize the transmission system.

The capability of Continuously Variable Transmissions (CVTs) to provide a continuous speed ratio change and smooth power flow has been widely recognized. These unique characteristics of CVTs make them especially suited for a variety of power transmission needs. Several studies have been accomplished in the past, to understand the power transmission characteristics of individual CVT concepts. However, few general analytical models and comparisons of different CVT concepts have been reported in the literature. In this work, different CVT concepts have been compared on an equitable basis in a selected operating envelope. Mathematical models of different CVT concepts have been developed from the published literature by normalizing the available information to allow comparison of different CVT concepts on an equitable basis. The models have been used next, to compute the efficiencies of individual CVTs at selected points covering the entire operating envelope.