To satisfy car buyers' tastes, automakers have been busily developing ways to squeeze more miles out of a gallon of gas. In addition to better engine design, an often-overlooked transformation has led to increased fuel efficiency: more and more, automakers are replacing heavier materials with lighter-weight plastics.
Generally known as "lightweighting," reducing a car's weight minimizes the load on the engine, so it needs less fuel. Replacing traditional materials with plastics has contributed significantly to lightweighting, so much so that experts estimate plastics make up 50 percent of today's automobiles by volume - but only 10 percent by weight. This progression toward plastics occurred over many decades, as cars also became generally more reliable, safer and better designed.
So if roughly half of today's car is made with plastics - where is all this stuff? This trend is probably most readily apparent inside the car. Other than windows and perhaps leather seats, nearly everything a driver or passenger sees and touches is made with plastics: the ceiling, visors, dashboard, instrument panel, door panels, carpeting, seat fabrics and cushions, seat belts, air bags … the list goes on. It may be less obvious on the exterior, but today's bumpers, quarter panels, headlights, taillights, grills, spoilers, running boards, and some other parts are generally made with plastics - or are rapidly headed in that direction. And take a look under the hood: a plethora of hoses and housings are made with plastics.
Lightweighting, and the resulting increase in fuel efficiency, contributes not only to the car owner's bottom line but also to a lighter environmental footprint. Better gas mileage saves money at the pump, and cutting fuel consumption can reduce a car's CO2 and other greenhouse gas emissions, as well as the impacts associated with energy production itself. Lightweighting contributes significantly to the efficiency of hybrid and electric vehicles, too.