KS Kolbenschmidt (Marinette, WI), a division of Rheinmetall Automotive, has refined its Liteks design for ultra-light, durable gasoline pistons. Compared to today’s in-production pistons, the company claims the latest design is another 10% lighter. With the fourth-generation Liteks, friction has been lowered by fine-tuning the basic piston structure and optimizing piston profile, which is asymmetrically barrel shaped. On the thrust and anti-thrust sides, differing and variable ovalities have been used along the skirt height; skirt width has also been reduced. As a result, friction is now down by 28% under full-load conditions and 7% under part load, according to KS Kolbenschmidt. Because of the newly configured skirt support, there is more homogenous stress distribution in the piston itself as well as further-enlarged ring zone undercuts. The pistons themselves owe their weight reduction to alloy KS 309 and the design engineers' exploitation of this material's specific advantages.