Mike Ramsey:

Operators of some of the largest U.S. truck fleets, including Lowe’s LOW +1.00% Cos., Procter & Gamble Co. PG +1.43% and United Parcel Service Inc., UPS +0.55% are accelerating a shift to natural gas fueled trucks, betting on new engine technology that promises to drop the cost of shifting from diesel fuel.

Home-improvement retailer Lowe’s wants its delivery company to shift all of its several hundred trucks to natural gas by 2017. P&G already has 7% of its trucks on gas and could reach as much as 20% within two years. UPS says it plans to buy 1,000 natural gas trucks by the end of next year. FedEx Corp. FDX +0.46% plans to shift 30% of its long-distance trucks to natural gas over the next decade.

The nation’s supply of relatively cheap natural gas is helping spur this shift. So are new natural gas engines that can power heavy-duty trucks that weigh up to 80,000 pounds. The first, a 12-liter Cummins Westport Inc. natural gas engine went on sale in July. Next year, Volvo AB, VOLV-B.SK +0.71% the Swedish heavy truck maker, will introduce a natural gas engine for its trucks.

Long-distance trucking companies, like Con-way Inc., CNW -0.13% Schneider National Inc., Swift Transportation Corp. SWFT +1.62% and Werner Enterprises Inc. WERN +0.26% are testing compressed natural gas and liquefied natural gas powered trucks as they awaiting more powerful engines and a nationwide fueling and repair infrastructure. Higher initial cost for vehicles, scant natural-gas vehicle suppliers and fuel availability have been impediments.