Autoblog Drives the 2008 Saturn Vue Hybrid (Visit this link)
Saturn uses the same mild hybrid setup used in the Aura and Malibu sedans. This system uses a 5kW motor/generator that takes the place of the conventional alternator. The motor/generator is belt driven off the engine crankshaft and provides automatic start/stop capability, some electric power boost and regenerative braking. The comparatively weak motor, combined with a nickel metal hydride battery with only 48V, obviously limits the capability of the system. During acceleration, the motor can basically act as an electrically-driven turbocharger providing up to 7hp extra when the battery has sufficient juice. Aside from that, it shuts down the engine when the vehicle comes to a stop and automatically restarts it when the brake pedal is released. Here is one place where the Vue shines. Unlike every other front wheel drive hybrid I've tried, this one had absolutely no shudder on restart. To varying degrees, the Toyotas, Nissan, Ford and the Saturn Aura I've sampled all had some powertrain shake when the engine was started and stopped. Not so the Vue, which was completely seamless. Another area that GM has improved from the Aura I drove last year is the transition from regenerative braking to friction braking only. Because of the limited battery capacity of the mild hybrid, there is no blending of regen and friction braking. Instead the regen, is overlaid on the friction braking. In the Aura, when the battery reached its maximum charge, the regen would just switch off and there would be a sudden reduction in deceleration. GM's engineers have revamped the controls to ramp out the regen so that there is no noticeable change as the regen goes away. As CUVs go, this one is worth a look, with reasonable interior space and sharp looks. Just don't expect a Prius (or Escape) beater at the pumps.