There is a car engineering strategy, known as “lightweighting”, aimed at developing lightweight structure cars to improve fuel efficiency, dynamics and driving. The lighter the car, the faster it accelerates, the more maneuverable and efficient it is. Using lightweight materials in car building leads to less strain on the engines, reduced fuel consumption and better car handling.
BMW knows that and strives for lightweighting to achieve better performance for its electric cars. To reduce car weight, the German carmaker uses innovative material at car building – the carbon fiber.
The carbon fiber (Carbon fiber reinforced polymer/CFRP, carbon fiber reinforced plastic or carbon fiber reinforced thermoplastic/CFRTP) is a light and highly resilient composite containing the carbon fibres and the matrix of plastic. It is 50% lighter than the steel and 30% lighter than the aluminum, but it is extremely strong and safe for being used in the industries requiring high strength-to-weight ratio and rigidity – aerospace, civil engineering, and, of course, car engineering industry.
BMW Carbon Production
Remarkably, the BMW is currently manufacturing the carbon itself in collaboration with a German producer of carbon fibers and composites SGL GROUP. In 2011, BMW and SGL Automotive Carbon Fibers opened a production plant in Moses Lake, Washington. The plant location is near a hydroelectric power source, because carbon-fiber production is the complex, energy-intensive process requiring considerable energy to convert precursor materials into carbon fibers. Using raw material shipped from Japan, the production facility now produces tons of carbon fibers annually to provide BMW with the required amount of high-grade CFRP.
Carbon Usage in BMW i3 and i8, Carbon Passenger Cell
BMW i brand models are the first mass production cars, featuring carbon in the construction, which results in improved car energy consumption, body stability, higher acceleration, yet higher passenger safety.
The i3 became the first electric car having most of its body parts and components fabricated from CFRP. The i3 is based on the LifeDrive architecture, which is BMW car construction structure developed exclusively for electric autos. It features the two main modules, the Life Module and the Drive Module. The Life module is the passenger cell, made of CFRP; the Drive module is the aluminum sub frame holding the propulsion components and the HV battery.
Due to material stiffness and resilience, BMW i8 and i3 with the carbon passenger cell deliver high safety level and protection in case of serious accidents. Yet, these supercars are lightweight enough to balance out the additional weight of the high-voltage lithium-ion battery.
The carbon passenger cell not only allows for a comfortable level of spaciousness in the car, it also saves the weight and boosts car dynamics.
As we’ve told last time, one of the core components of BMW EfficientDynamics is using lightweight materials in electric car construction to lessen power consumption and emissions. It allows for efficiency, dynamic performance and improved agility, so much needed for safe megacity driving. One of BMW’s task within EfficientDynamics concept – “less weight, more speed” – is achieved thanks to the use of the carbon in the passenger cell, aluminium in the chassis, premium quality steel in the body and innovative magnesium alloys in the engine. Fuel consumption is decreased, while the car performance is improved.
Think BMW will keep making cars using the carbon?
Now you know why BMW i chooses the carbon to produce its luxurious electric cars. The advantages of using this strong and significantly lighter material in car engineering are obvious. Though of course, the carbon production is expensive, and it adds to the car price tag – which is a huge pitfall.
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