Autocar drives the BMW Active Hybrid 7

7 Series | October 30th, 2009 by 1
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UK magazine Autocar is one of the first auto publications to sit behind the wheel of the upcoming BMW Active Hybrid 7. The first production ready BMW hybrid uses a different electric drive setup from the X6 Hybrid and it’s being considered a mild hybrid. The system was developed in collaboration with Mercedes Benz. The upgraded V8 twin-turbo with High Precision Direct Injection runs together, at the same time, with a 3-phase synchronous electric motor which is positioned between the engine and the torque converter. The electric motor generates approximately 20 hp and peak torque of 155 lb-ft.

The “pumped up” V8 twin-turbo engine produces 40 horsepower more than the engine found in the 750i/Li models to a total of 400 horsepower. The overall combined output is being advertised at 455 horsepower and 516 lb-ft of torque. It runs from 0-62 mph in only 4.7 seconds (as tested by Autocar )

With these preliminary data, let’s take a look at what Autocar reports:

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What’s it like?

Despite the advanced technology and various modifications – all of which add 100kg to the kerb weight – the Active Hybrid 7 instantly feels more muscular than the 750i, thanks to the added power and extra torque.

The upshot is a car that wafts along serenely at town speeds and can be coaxed into a rapid cruise at ridiculously low revs; the combined efforts of the petrol engine and electric motor provide the Active Hybrid 7 with enormous low-end urge and a pleasingly relaxed gait at motorway speeds that is further enhanced by the 7-series’ excellent gearing and overall refinement.

BMW’s claim that the Active Hybrid 7 boasts the performance of a V12 is fully backed up by the claimed 0-60mph time of 4.9sec, which makes it 0.3sec quicker than the 750i.

Given the performance, its combined cycle consumption of 30.1mpg and CO2 rating of 219g/km is outstanding, also bettering the 750i by 5.3mpg and 47g/km respectively in short-wheelbase guise.

The petrol engine shuts down when you brake to a standstill to conserve fuel, leaving you contemplating the silence until you step away from the brake again, at which point the big V8 bursts back to life. There’s no characteristic turbine whirl of the starter motor because there is none. Instead, the automatic stop-start function is achieved via the main electric motor.

Full article at Autocar