DETROIT — High oil prices have pushed the auto industry to go green in more ways than improving fuel economy.

At a time of plummeting vehicle sales and production, automakers and suppliers are also being squeezed by soaring prices for key automotive commodities such as steel, aluminum and plastics.

Metals have long been recycled, but now automakers and suppliers are increasingly turning to recycled plastics to offset rising costs, and recycled plastics are showing up in bumpers, splash guards and under the hood. The savings range from a few cents a pound to half the price of new plastic, which accounts for a third to half of the price of many components.

The downside is that as a piece of plastic is recycled, its quality degrades, becoming, for instance, more brittle or less durable. So suppliers often mix recycled plastics with new material. Bumpers, for instance, often have as much as 20 percent recycled plastic.

“A lot of people, especially in this economy, are trying to cut costs, without cutting quality,” said Lora Herron, a bio and recycled materials engineer at General Motors Corp. “Recycled plastics are a really good way to do that, as long as you’re careful about it and watch your quality.”

In the back of the sprawling Flint, Mich., plant of recycler ACI Plastics, there’s an air-conditioned laboratory where the company’s technicians test the strength and other characteristics of the plastics that are recycled in the plant to assure customers that the plastic will meet their specifications.

ACI takes scrap from the manufacturing process, such as imperfect bumpers and plastic parts from discarded vehicles. ACI shreds them up, often removes their paint and turns them into recycled pellets that can then stand on their own or be mixed with new materials.

Scott Melton, ACI’s president, expects the company’s $17 million in sales to grow 20 percent next year.

“People are realizing there’s a greater value in their scrap, and the best thing they can do is recycle it,” said Melton.

Even the dust that comes off of bumpers and dashboards as they’re chipped up in a grinder is collected, melted and turned into plastic pellets.

To save money on raw materials, automakers and suppliers also are doing what they can. Honda Motor Co. collects the plastic caps placed over engine openings as they are being built so they can be sold for recycling.

Last year, Dearborn, Mich., interiors supplier International Automotive Components North America started to recycle 20-pound slabs of plastic, about the shape and size of a tire, that are pushed out of injection molding machines to clear those machines to make parts in a different color.

IAC used to send those pieces to landfills because they were too thick to send through the company’s plastic grinders. But now, IAC thins the plastic so it can be ground up and used in interior parts.

“We want to reduce what we’re sending to landfills,” said Susan Kozora, IAC’s manager of materials engineering.

Of the 50 million pounds of plastic resin the company buys every year, 10.5 percent is recycled.

Already, Ford’s fender liners — on the inside of a fender to protect it from debris — are made of recycled automotive battery casings, said Claudia Duranceau, senior research recycling engineer at Ford.

GM uses recycled water bottles to make the carpet and floor mats in the Pontiac G8. It also uses recycled nylon for the exterior mirror casings in its crossovers, such as the GMC Acadia.

Recyclers are “putting out a product that is really competitive,” said Jerry Powell, editor of Plastics Recycling Update in Portland, Ore.