Those soybeans you run through your combine could make the machine's engine run better and last longer.

SoyShield, a soy-derived diesel fuel additive that rolled onto the market a year ago, improves lubricity (lubrication capacity), boosts fuel efficiency and extends engine life.

In the bargain, SoyShield reduces exhaust emissions.

"One gallon of SoyShield treats 500 gallons of No. 2 diesel fuel," says Jay Shields of Schaeffer's Specialized Lubricants, St. Louis, MO, which markets the additive.

"At that ratio, the treatment increases fuel cost by 3 cents/gallon," he adds.

But it makes No. 2 diesel the equivalent of premium diesel fuel, which typically costs 5-7 cents/gallon more at the pump.

"Soybean oil provides the main part of increased lubricity," Shields continues.

"We incorporate other additives to clean injectors and boost mileage. And we have anti-gel additives to winterize SoyShield for cold-weather operation."

The multifaceted fuel additive was developed three years ago with funding from the Minnesota Soybean Research and Promotion Council.

Paul Nazzaro of the Massachusetts-based Advance Fuel Solutions did the market development work under contract to the National Biodiesel Board.

"To complement soybean oil, we blended conventional petroleum additives, and I began looking for the right company to market this value-added product," says Nazarro.

"Truck-fleet operators were a potential market, but fleet owners are interested first in fuel price per gallon; secondly in fuel quality."

When the company's network of 300 distributors held a convention last January, Jeff Horvath, president of the National Biodiesel Board, made the SoyShield presentation to them.

"We proposed that we first service the ag market," says Shields. "For one thing, it made sense to put the additive in the hands of the people who grow the soybeans.

"Farmers are a slow sell, but they're loyal. Farm business typically starts off slowly, but if you've got a product farmers have confidence in, the market builds. In just a year, we're seeing a lot of repeat orders," Shields says.

To reach Schaeffer's Specialized Lubricants, call 800-325-9962, or check the Web (schaef feroil.com).