Oct 4 2009 Steve Hughes
AUDI has developed an ultra-lightweight version of its sleek A5 Coupe and Sportback models, which it believes will be a blueprint for all cars of the future.
The ditching of traditional steel in favour of aluminium, carbon fibre and magnesium reduces the weight significantly, which makes it more economical, less polluting and safer.
Audi believes that by doing this it can safeguard the future of executive and sports models that might otherwise become victims of the growing political correctness witch-hunt against them.
The principle can be applied to all types of vehicles from large 4x4s to smaller superminis and sports models, with massive advantages for the environment.
In the case of the ultra-lightweight A5 Coupe there is a 40 per cent weight difference between the use of the two types of materials, which amounts to a significant reduction of 100kg.
This enables the car to use a relatively small four-cylinder petrol engine of just two litres to achieve the same performance as that of a 3.2-litre V6 in the case of the same car with a steel body.
The smaller engine generates 210bhp in comparison to 265bhp for the V6 but the all-important power to weight ratios are little different. This means a massive economy gain and a tremendous reduction in emissions.
Every 100kg saved in weight reduces fuel consumption by about a litre for every 120 miles travelled, which in the case of a car with a range between fill-ups of about 600 miles is a significant fuel saving of five litres.
There is also a corresponding reduction in CO2 output of about ten grams for every kilometre travelled, which with an average of about 20 million vehicles on UK roads at any time makes cars collectively much kinder to the environment.
The use of lightweight materials for the body means that other components can be lighter too, including the chassis to which it is attached plus the suspension, transmission, fuel tank, brakes and a host of other associated components.
Audi says that reducing the weight of cars of the future is of infinitely more value than the development of electric vehicles, which are even heavier than conventional cars because of the weight of the batteries that they have to lug around.
Audi technical development boss Michael Dick, says: ``Lightweight design is the foundation of our entire approach to improving efficiency.
It makes a significant contribution to dynamic potential and efficiency, helping to conserve resources and reduce operating costs. The electric drives of the future will add additional weight to the car and will initially only offer a limited range, making systematic lightweight design all the more important.''
Lighter vehicles are significantly more responsive when cornering and avoiding collisions. They cause less damage in the case of impact and can achieve the same levels of body rigidity and occupant protection as traditional steel-bodied models.
Audi has produced more than half a million models with aluminium bodies in the last 15 years including Lamborghinis, the highly-acclaimed R8 supercar and the quirky A2 supermini which was withdrawn prematurely after proving a sales disaster.
Manufacturing costs have tumbled with advances in the notoriously-difficult area of aluminium automation, which has risen from 25 per cent to 80 per cent of the production process.
However, whilst car companies may be perfecting the use of a combination of futuristic lightweight materials the concept of aluminium-bodies is not new.
NSU built the Type 8/24 with a body made entirely of aluminium as long ago as 1913.