There’s a warm blue (for the color of the flame when natural gas is ignited) glow being cast over the spec’ing choices of more and more truck fleets seeking to go green, both to gain green by spending less on fuel and to demonstrate environmental sensibility by switching to trucks powered by either compressed natural gas (CNG) or liquefied natural gas (LNG).Natural gas (NG) is starting to catch fire in the truck-fleet market. Consider that a recent survey, conducted jointly by ACT Research and Transport Capital Partners, found that the “growing interest in natural gas by carriers [is] encouraged by the large difference in [fuel] price.” Slightly more than half of the fleets in the survey are considering adding at least some NG trucks the next time they buy new.Indeed, the positive impact on truck fleets of switching from diesel to blue power can be tremendous.

Bear in mind, though, that cost comparisons for both CNG and LNG vs. diesel is often expressed via the measure known as diesel gallon equivalent (DGE).“Fleets purchasing natural gas vehicles today are purchasing fuel at a significant reduction from diesel,” points out Robert Carrick, Freightliner Trucks’ vocational sales manager-natural gas.“The price of natural gas over the past four years has been consistently lower than diesel, in some cases by as much as $2 DGE,” advises Andy Douglas, Kenworth’s national sales manager for specialty markets. “It’s no wonder natural gas has drawn increasing interest among truck and fleet operators.”

“Current indicators point to [the continuance of] low-cost natural gas,” reports Curtis Dorwart, Mack’s vocational marketing product manager. “We expect CNG to continue to be 40 to 50% the cost of diesel and LNG to be 30 to 40% the cost of diesel.”

When it comes to switching to NG engines, diesel-powered fleets must first determine whether CNG or LNG or both are a fit for the duty cycles of their operation.CNG provides a shorter operating range as well as generally lower vehicle gross weight limits than LNG, so it is typically selected by local/regional fleets that are centrally fueled.LNG, on the other hand, is the NG fuel of choice for longer-haul operations, thanks to the greater operating range delivered by its onboard storage.

Naturally, both engine makers and truck builders have been responding to the marked upswing of interest in natural gas as an alternative fuel by developing more engines designed to run on CNG and LNG and by making these powerplants more widely available to truck buyers. That’s why this year, fleet owners will have an even wider choice of natural gas-specific engines and truck models. Here is the latest news and views on NG engine offerings and developments for 2013 and beyond as relayed by the major engine manufacturers and truck builders.