Pale ‘green’
We’re supposed to keep quiet about this… we are driving under electric power. The designers of the BMW 5-Series Hybrid have gone to great lengths to make the method of traction as inconspicuous and simple as possible.
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- The way the hybrid system is functioning can be monitored by means of the graphic presentations on the computer screen although there is little scope for the driver to influence the processes at work.
The way the hybrid system is functioning can be monitored by means of the graphic presentations on the computer screen although there is little scope for the driver to influence the processes at work. There is an ‘Eco Pro’ drive mode which can be selected… this puts all the systems on a low energy and low consumption regime. But a pure electric mode, as found on Toyota Prius or Lexus GS 450h models, is conspicuous by its absence. Even the Audi A6 Hybrid offers this option, permitting pure-electric drive at the push of a button, albeit for only three kilometres and at speeds not exceeding 60 kilometres an hour.
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- The push for the ActiveHybrid comes from a turbo boosted straight six mill producing 306 horsepower (225 kW) supported by a 55 horsepower (40 kW) synchronous electric motor. The system output is around 340 horsepower and the driver has a maximum of 450 Nm of torque at his disposal.
Efficiency re-defined
The push for the ActiveHybrid comes from a turbo boosted straight six mill producing 306 horsepower (225 kW) supported by a 55 horsepower (40 kW) synchronous electric motor. The system output is around 340 horsepower and the driver has a maximum of 450 Nm of torque at his disposal. The fuel consumption is far from stellar… the BMW Hybrid officially calls for an average of from 6.4 to 7 litres of petrol per hundred driven kilometres. By way of comparison the slightly smaller but similarly powered (343 horsepower) Lexus GS 450h gets by with just 5.9 litres. It is obvious that the 3-Series Hybrid… with essentially the same drive technology as the 5-Series model… will have to do better. It is to be noted also that the variance in the fuel consumption of the 5-Series ActiveHybrid is also due to differences in tyre characteristics and only with energy-saving rubber can the best results be achieved.
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- The lithium-ion battery array is located behind the car’s rear sears and can only be installed in an upright position, resulting in a reduction in the load carrying capacity of the boot… now taking at 375 litres 145 litres less than a normal 5-Series can handle.
Alibi hybrid
The lithium-ion battery array is located behind the car’s rear sears and can only be installed in an upright position, resulting in a reduction in the load carrying capacity of the boot… now taking at 375 litres 145 litres less than a normal 5-Series can handle. The batteries are liquid cooled and comprise 96 cells using the very reliable lithium-iron phosphate technology. This is a variant of lithium-ion battery and has in this application a capacity of 1.3 kWh. A purely electrically driven model like the Nissan Leaf has, in comparison, twenty times as much battery capacity.
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- the interaction of the turbo boosted six-cylinder engine and the electric motor… sending the combined power via an eight-stage automatic transmission to the back wheels… is very harmonious. A kick-down brings out the best of both power plants and makes for a zero-to-a-hundred time of 5.9 seconds… and this for a car tipping the scales at almost two tons. The standard 535i takes a tenth of a second more for the sprint.
Running on electrical power alone the BMW has a range of four kilometres at the most at a maximum speed of just 60 kilometres an hour and a very light foot on the accelerator. If the driving is uphill then not even the gentlest touch will help and after just a few hundred metres the petrol engine will cut in. However the interaction of the turbo boosted six-cylinder engine and the electric motor… sending the combined power via an eight-stage automatic transmission to the back wheels… is very harmonious. A kick-down brings out the best of both power plants and makes for a zero-to-a-hundred time of 5.9 seconds… and this for a car tipping the scales at almost two tons. The standard 535i takes a tenth of a second more for the sprint. The premium sedan has thus not lost any of its dynamism but nor has it gained substantially in this respect.
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- The prominent display of the ‘Hybrid’ badge on the ‘C’ pillar of the 5-Series auto makes it clear that in the premium segment it is all about prestige.
Prestige for Americans
Alone the prominent display of the ‘Hybrid’ badge on the ‘C’ pillar of the 5-Series auto makes it clear that in the premium segment it is all about prestige. It will be in the United States and in Japan that buyers for the partially electrically driven model will be found whereas in Germany this 5-Series version will languish in the shadow of the diesel powered cars. The price, for sure, will make this inevitable… at 62,900 Euros the ActiveHybrid will be around 12 thousand more costly than a normal 535i. The very limited demand for hybrid vehicles in Germany comes as no surprise for the Munich car maker… here it is impossible to claim for them a financial advantage in comparison with diesel powered cars.
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- It will be in the United States and in Japan that buyers for the partially electrically driven model will be found. It is however probably that the hybrid ambitions of the Bavarian manufacturer will be enhanced through the future co-operation with Toyota.
A true plug-in hybrid bearing the BMW logo… one with more power and one which can be re-charged from a domestic plug… will not be available before 2014. At the moment other marques such as Opel, Ford and Toyota appear to be in the lead. It is however probably that the hybrid ambitions of the Bavarian manufacturer will be enhanced through the future co-operation with Toyota. Both concerns have announced their intention of working together on alternative drive systems and battery technology.
