By Dan Bewley, for NEWS 9

TULSA, Okla. -- A Tulsa landscaping company has switched from gasoline to propane in an effort to cut fuel costs.

Alan Roark with Roark Landscaping had his mowing fleet converted to propane. Twenty mowers and three riding lawn mowers now all sport a propane tank.

"The fuel prices have got to a point where it makes sense," Roark said.

Roark has been thinking of converting for the past three years. During the winter he finally had it done at a cost of about $500 a mower.

Many of his contracts were signed when gas was only $2.50 a gallon. Now it's pushing $4.00 and there's no sign of stopping. Roark expects the propane will save him at least 30 percent in fuel costs this year.

In addition to the cost savings, Roark said propane is much friendlier to the environment.

"If you change the oil and go back a month later, check the oil. It's as clean as it was when you put it in," Roark said. "It doesn't have the soot and carbon you get from a gasoline engine."