A 2011 BMW ActiveHybrid 7 is really a hybrid that will never remind you of a Prius in any shape or form. Gasoline efficiency is exactly what you think of when you think hybrid however the BMW hybrid is not that fuel efficient. Even though the 2011 ActiveHybrid 7 is going to save on fuel compared to its other 7-series siblings, its ride in stop and go traffic is iffy and the power steering gets turned off in idle stop. It can do a good job of integrating raw car power with the fuel efficiency of hybrid technology but there are numerous quirks that get in the way.
The extra energy that is provided by a hybrid system is normally used by most automakers to have a smaller gasoline engine, but not BMW. Most hybrids reduce gasoline costs while maintaining power, but BMW saw the extra power, and decided to make their cars go faster. Like the standard BMW 750i, the 2011 BMW ActiveHybrid 7 has a twin turbo direct-injection 4.4-liter V-8 engine. The only distinction is the inclusion of an electric motor than gets its power from a 120-volt lithium ion battery pack. This makes the gasoline economy of the ActiveHybrid 7 better than the 750i, and with a lot more horsepower in addition.
The ActiveHybrid 7 should basically be considered as a mild hybrid system because the car is not able to drive completely under electric power. It is similar to the Integrated Motor Assist System of the Honda wherein the engine should shut down at stops and will add boost during acceleration. When driving, you will have no idea that it is a hybrid except when you see a blue are in the fuel monitor to show that electricity is being regenerated. But if you come to a stop, you are going to feel the engine go silent and the tach needle go to zero. Despite the proportions of the engine, the car starts up very smoothly when you take the foot off the brake pedal.
While you’re waiting at a traffic light that is really long, that is when the idle stop system is useful, but not quite as well in stop-and-go traffic. For whatever reason, your car will turn off for 5 seconds at a time even in stop-and-go traffic. The degree of energy is impressive but it does take some getting used to because the car will lunge forward even with a light touch on the accelerator. The way the car is designed, it is not a green car but a car that uses the hybrid system to add more power while improving fuel efficiency somewhat.
The 2011 BMW ActiveHybrid 7 comes with the best gas mileage in the BMW 7 series family however it only gets 20 miles per gallon. Pretty good for the high end vehicle it is, but nothing breathtaking for a hybrid.