Light-Weight Cars Improve Gas Mileage and Performance

Carmakers have to find a delicate balance between fuel economy, safety and performance in order to make a successful car. Safety and fuel economy are mandated by the government, and the requirements for both get more demanding every year. With the upcoming change in CAFÉ standards, which will make California’s fuel economy standards the rule for the entire country, automakers will be forced to cut the gas mileage of their cars dramatically.

The challenge then, is to find a way to make cars as fun to drive as possible without compromising safety. Instead of focusing entirely on developing more powerful, more fuel efficient engines, as has been the norm in recent years (direct injection engines are the most recent breakthrough, which allow engines to burn fuel more thoroughly than traditional fuel injection does, increasing gas mileage and horsepower), some carmakers are putting their engineers to work to reduce weight in their cars.

Porsche has already said publicly that it believes weight reduction is more important for its sports cars than an increase in horsepower. Now Audi has also shifted its focus toward creating lighter cars, according to Autocar.

Audi has created a prototype of a lightweight version of its MLP, which is the platform underneath the A4, A5 and Q5.

Weight reduction of Audi’s new platform will be the “basis for the electrification of the car,” according to Michael Dick, director of technical development for Audi.

Engineers managed to cut 800 pounds off the weight of an Audi S5 (pictured below) by using a spaceframe with a new light-weight hybrid steel and aluminum frame.

With the lighter body and frame, Audi has managed to cut 8 seconds off of the S5’s lap time on the Nürburgring. That’s impressive, but what’s even more so is that the lighter car had Audi’s 230-hp four-cylinder engine while the factory S5 it beat comes with a 345-hp V8.

Audi’s new space frame should be strong enough to meet safety requirements but light enough to deliver good gas mileage and support an electric power plant. The only potential issue is the added cost of the light-weight MLP platform, but Audi says it is able to change the mixture of steel and aluminum in order to reduce cost at the expense of more weight as needed.

2009 Audi s5 picture