As the 594 miles from Wall, South Dakota, to Butte, Montana, on the "Southern Fried Fuel" expedition roll by, Middle Tennessee State University researcher Cliff Ricketts realizes a decision he made months ago was a wise one.

From the suggestion by an MTSU agriculture student, he bought a 1991 Dodge Ram diesel pickup as the backup for the 1981 Volkswagen Rabbit diesel.

When the Rabbit continued to have water pump, radiator and overheating issues, Ricketts, in baseball terms, called on his ace reliever to earn the save of the day.

In reaching Billings, he drove 364 miles on one-half tank of biodiesel from chicken fat -- and plenty left in the tank as the team moved forward in hopes of completing driving 3,500 miles from Key West, Florida, to Seattle, Washington, on the fuel, which has been perfect and had no part in the mechanical issues.

"It's been great," Ricketts said of the Dodge Ram coming through in the clutch. "We cashed in on the expectations of the backup vehicle. We're getting excellent mileage (20 miles per gallon or more)."

The group, which includes MTSU senior Ben Black of Lascassas, Tennessee, will attempt the final 600 miles to Seattle Tuesday, March 10. Other team members include Terry Young of Woodbury, Tennessee; Paul Ricketts of Versailles, Kentucky; and Mike Sims of Jackson, Michigan.

Knowing petroleum prices will rise again, Ricketts, an MTSU School of Agribusiness and Agriscience faculty member, wants his "research to show and test the viability of animal fat as a fuel, using it 100 percent and comparing it to the performance of biodiesel from vegetable oil."

"More importantly, my research is to show and illustrate that there are other viable alternatives to petroleum oil from the agricultural industry," he added.

"This animal fat is another alternative fuel that could be used in time of a national emergency."

Ricketts' 38 years of research includes ethanol, methane from cow manure, biodiesel from soybean oil and other grain crops, solar electric, hydrogen from water and biodiesel from waste by-products and used vegetable oil.

The MTSU professor uses older vehicles to stay within his budget. His original '81 Rabbit was destroyed in 2014 when a student working on the truck inadvertently blew the engine.

Butte temperatures dropped to 22 degrees by early morning March 10, causing concern for the team. They left the truck running overnight to keep the fuel from gelling.

For at least a nearly 100-mile stretch of Interstate 90 in Idaho, the team will use used cooking oil from MTSU dining facilities.

The "Southern Fried Fuel" expedition will go through Spokane, Washington, then they will drive more than 250 miles to reach Seattle Tuesday to complete the 1,850-mile second leg of the trip.

Since March 8, they have driven through Missouri, Iowa and South Dakota.

The first segment of the Key West, Florida, to Seattle expedition ended Nov. 11 in Grain Valley, Missouri, near Kansas City. A transmission issue postponed the trip nearly four months.