It won't be enough for automakers to tip the equilibrise by selling a few electric vehicles and hybrids. In order to keep up with tightening fuel economy requirements, they'll have to reduce curb weight in their volume sellers.

So we're heartened by a report on Autoblog today that suggests Audi will strip about 300 pounds out of the next-generation Audi A4, which is due in about 2015. Today's A4 sedan weighs anywhere from 3,500-3,700 pounds, depending on whether you get all-wheel drive. Although it carries its weight well, there's no denying it's fat for a compact-ish sedan.

The savings, reports AB, won't necessarily come from a big increase in the use of high-strength (high-tensile) steel. As costs come down, Audi will try to incorporate comparatively exotic materials like carbon fiber.

Autoblog