Kia Motors is carrying out R&D toward the goal of making our cars 10% lighter than they currently are by 2015. A 10% reduction in weight results in enhancements of 3.2% in fuel economy, 8.5% in acceleration performance and 19% in steering wheel maneuverability. The vehicle also becomes 1.6 times more durable and emits 3.2% less CO2. To lighten the vehicle body, steel is replaced by aluminum alloy, resin and other lighter materials; the number of parts is reduced through the adoption of modules; and unnecessary weight is minimized through design optimization. Research into the use of lighter materials is focused on decreasing the thickness and weight of the materials while maintaining performance and durability.
In K7 (Cadenza), our effort to go lightweight begins with the wiring. Consisting of intelligent, electronic modules, the wires pass through the engine room and the interior of the vehicle in an optimized path. Moreover, an automotive structural adhesive is used instead of welding. As a result, K7 is one of the lightest vehicles in its class.
As for K5, its heating, ventilating, and air conditioning unit case is the first in Korea to be made of glass bubbles, a high-strength plastic. Polypropylene is generally the material of choice for embedded automotive components, but K5’s heating, ventilating, and air conditioning unit case is over 10% lighter than its polypropylene counterpart.
We plan to use glass bubble heating unit cases in newly released models. K5’s center pillar is made of ultra-high strength steel produced by hot stamping. Hot stamping is a method of reinforcing a given material by pressing it at a high temperature and then quickly cooling it. The ultrahigh strength steel making up K5’s center filler has reduced the number of parts and weight of K5 compared to its predecessor. It has also made the car strong and durable; K5 received the highest rating in a side-impact test.