OKLAHOMA CITY (AP) — Amtrak officials say they have no beef with using cattle-based biodiesel to power their Heartland Flyer train.

The railroad said Monday that a mix of beef tallow and diesel fuel effectively powered the passenger train's 3,200-horsepower engine. Following a yearlong test on the rails between Oklahoma City and Fort Worth, Texas, an evaluation found that the fuel blend met industry standards, engine wear was limited and emissions were below federal limits for the type of engine using it.

Roy Deitchman, Amtrak's vice president of environmental, health and safety vice president, said the railroad was able to replace about 35,000 gallons of diesel with a locally produced renewable fuel during the test.

Tallow is often used to make soap or animal feed. Previous tests found that engines running on a biodiesel mix had lower emissions, but further testing was needed to ensure its gaskets didn't wear prematurely with an animal-based product in the engine. Amtrak said the blend resulted in no more wear than usual.

The results, presented last week at a railroad environmental conference at the University of Illinois at Urbana-Champaign, also showed less pollution.

Amtrak used a $274,000 federal grant from the Federal Railroad Administration and worked with the Oklahoma Department of Transportation to test the fuel in a General Electric P32-8 locomotive. It launched the test during Earth Day festivities in Oklahoma City in 2010.

The train stops daily at Oklahoma City, Norman, Purcell, Pauls Valley and Ardmore in Oklahoma and Gainesville and Fort Worth in Texas. State governments help fund its operation.

While biodiesel can be more expensive than traditional fuel, it can reduce demand for oil.