BMW 5 ユーザーズマニュアル

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BMW 
Media 
Information 
 
11/2009 
Page 30
 
The petrol engines in the new BMW 5 Series:  
a perfect combination of innovations for supreme efficiency. 
Offering the spontaneity, fast-revving performance and refinement so  
typical of the brand, combined with unparalleled efficiency, the petrol  
engines featured in the new BMW 5 Series Sedan come with a standard  
quite unparalleled in the market. Both the eight-cylinder power unit in  
the top-of-the-range BMW 550i and the three straight-six engines come  
with outstanding technical innovations created in the context of  
BMW EfficientDynamics. And the specific combination of technologies  
gives each of the four drive units its own quite unique characteristics.  
The most important feature shared by all petrol engines is fuel supply by 
means of second-generation direct fuel injection. Already well-known as  
High Precision Injection, this advanced system uses injectors positioned  
in the middle between the valves and in the immediate vicinity of the spark  
plug for the precise dosage of fuel, measurably reducing fuel consumption 
also in everyday traffic.  
A particularly efficient version of High Precision Injection is to be admired in 
the six-cylinder engines driving the new BMW 528i and the new BMW 523i. 
Direct injection in the lean-burn mode gives these models particularly good 
fuel economy. Referred to as stratified charging, this process forms various 
interacting layers of different fuel/air mixtures within the combustion chamber, 
the share of petrol in the mixture decreasing continuously with an increasing 
distance from the spark plug. A particularly rich and therefore ignitable fuel/air 
mixture is therefore available only in the direct vicinity of the spark plug.  
As soon as this mixture is ignited, the leaner layers at a greater distance from 
the spark plug will also burn in a clean and consistent process.   
In the V8 power unit of the new BMW 550i and in the straight-six engine 
featured in the new BMW 535i High Precision Injection is combined with 
turbocharging. BMW TwinPower Turbo Technology provides power and 
performance characteristics a naturally-aspirated engine would only be able  
to offer on much larger capacity, making it heavier and obviously consuming 
more fuel and generating more emissions.  
The eight-cylinder with BMW TwinPower Turbo and High Precision Injection 
is the only petrol engine of its kind with a turbocharger and catalysts arranged 
within the V-section between the two rows of cylinders, and at the same time 
it is the world’s most efficient power unit in its performance class. Compared 
with its predecessor, the new BMW 550i offers 30 kW more power on 
approximately 5 per cent less fuel.