Cars shed weight to become agile, fuel-efficient

Shedding weight is always a delight. And, carmakers are increasingly looking to achieve this by making vehicles lighter. The weight reduction — necessitated by the increasing use of new features and components — in some cases is up to 10 per cent, which in turn provides additional mileage.

Take the case of the new Dzire, launched by Maruti Suzuki on Tuesday. It is 10 per cent lighter than the outgoing Dzire. The weight reduction of 105 kg is a result of a new platform and the use of high-tensile steel, among other things. The diesel Dzire now weighs 950 kg against the previous model’s 1,055 kg, while the petrol variant weighs 855 kg, down nine per cent.

The reduced weight offers a higher fuel mileage of 6.8 per cent in the diesel variant and 5.5 per cent for petrol Dzire.

“With the progress in vehicle technology and features, the number of equipment is going up. However, the requirement of fuel efficiency from customers is not reducing. It is rather increasing. There is a limited improvement possible in the engine and its fuel efficiency,” said C V Raman, executive director (engineering), Maruti Suzuki — the country’s biggest carmaker.

In order to make an engine lighter, companies try to use aluminum parts or plastic parts. Already many parts have been shifted from metals to plastic. Such parts include the head cover of engine (shifted from metal to plastic) and brackets that are changing from metals to plastic or aluminum.

These do not suffice, however, as new features like air bags and anti-lock braking system are getting added to every new car. “But we want the weight to come down. So, you develop a new platform, you use a lot of high-tensile steel. You reduce the weight and improve rigidity through a combination of lighter engine and platform,” said Raman.

Maruti Suzuki’s new Swift (likely launch in early 2018) will be more than 12 per cent lighter than the existing model.

Luxury carmakers are also following this trend. The new Audi A4, launched in February, weighs 120 kg less than the earlier model and offers seven per cent higher fuel efficiency. The new Audi Q7, launched in December 2015, is lighter by up to 300 kg, making it more dynamic and agile in character, and it has 22 per cent better fuel efficiency.

In the case of Maruti’s popular bestseller Baleno, there was a marked improvement in weight since it was made on the fifth generation platform. “When we moved from second generation Swift to the Baleno, there was a marked improvement, even though the engine was same. This happened due to a new platform. If we had made Baleno on the previous platform, it would have been heavier by 100 kgs,” said Raman.

Maruti wants even lighter weight for future cars. Raman said weight reduction was a process. “Every engineer is given a weight target for part, sub systems and systems when a vehicle is conceptualised. He has to design at particular cost and also weight. This is critical to achieve lighter weight and (better) fuel efficiency. It is also critical to make suppliers work on new technology as over 70 per cent parts usually come from the suppliers,” he said.