 Research and Development was advancing in the 1990s with projects such as the early BMW 5 Series (E34) CVT hybrid-electric vehicle  In 1992, Volvo ECC was developed by Volvo.The Volvo ECC was built on the Volvo 850 platform.In contrast to most production hybrids, which use a gasoline piston engine to provide additional acceleration and to recharge the battery storage, the Volvo ECC used a gas turbine engine to drive the generator for recharging.