For years, companies that rely heavily on fuel have experimented with substitutes for conventional gasoline and diesel, including natural gas, electricity and biofuels.

Now, one company is moving beyond the test phase. On Wednesday, UPS announced that it will buy as much as 46 million gallons of renewable diesel over the next three years, helping the company reach a goal of displacing 12 percent of the petroleum-based fuels in its ground fleet by 2017.

The renewable fuels, from three suppliers, are chemically so close to their petroleum-based counterparts that they can replace them in engines and pipelines. They are made from an array of bio-based sources, including palm and waste oils, and animal fats.

“It’s actually as good or even better from a performance perspective as traditional diesel,” including easy starts in cold weather, said Mike Whitlatch, vice president for global energy and procurement at UPS.