What is it?
Conventional logic suggests hybrid systems are best used for their added fuel saving effect. The problem is that they only begin to make financial sense if they are applied to exclusive upper-end luxury models – the likes of which attract well-to-do customers for whom fuel efficiency is typically not an overriding priority.
Why not alter the primary focus to out-and-out performance enhancement, then? That, in essence, is the thinking behind the new BMW Active Hybrid 7.
BMW has developed two different hybrid systems. The first, used by the Active Hybrid 7, is a mild hybrid system that provides assistance to the petrol engine via an electric motor but, due to the small capacity of the battery, does not support electric-only propulsion. Rather, the petrol engine is always in operation when you are moving forwards.
Using the 750i as a basis, its twin-turbocharged 4.4-litre petrol engine gets greater boost pressure for an added 42bhp and 37lb ft, taking its output up to 444bhp and 479lb ft.
It is assisted during step-off and under light to moderate acceleration by an electric motor housed within a new eight-speed automatic gearbox. The brushless unit operates in total silence, drawing energy from a lithium ion battery mounted in the boot to take the Active Hybrid 7’s overall reserves to 459bhp and 516lb ft.
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.