General Motors then introduced their BAS Hybrid system, another mild-hybrid implementation officially released on the 2007 Saturn Vue Green Line. Its "start-stop" functionality operates similarly to the Silverado, although via a belted connection to the motor/generator unit. However the GM BAS Hybrid System can also provide modest assist under acceleration and during steady driving, and captures energy during regenerative (blended) braking. BAS Hybrid offered as much as a 27% improvement in combined fuel efficiency in EPA testing of the 2009 Saturn VUE. The system can also be found on the 2008–2009 Saturn Aura and the 2008–2010 Chevrolet Malibu hybrids.