LOUISVILLE, Ky. — Cummins has vowed to improve fuel economy over its existing engines by a further 2% this year.

The 2% gain is attributed to reduced parasitic losses and comes on top of a 2% gain achieved this year due to combustion and system optimization and a 3-5% gain in 2010 as a result of the use of selective catalytic reduction (SCR), the company announced.

The 2013 engine line will use Cummins’ existing high-pressure common rail fuel system, its variable geometry turbocharger and its integrated electronics.

Cummins also announced its 2013 engine line will meet the EPA/NHTSA 2014 greenhouse gas/fuel economy standards one year earlier than required.

“Our engines are meeting the 2014 fuel efficiency and GHG standards a full year early,” announced Rich Freeland, Cummins vice-president and president of the engine business during a press conference here preceding the Mid-America Trucking Show.

Cummins’ 2013 engine line will continue to rely on SCR, combined with an integrated diesel particulate filter (DPF) in a package the company now calls its Cummins Emissions Solutions EcoFit Ultra-Low Emissions exhaust aftertreatment system.

Cummins also announced it is expanding its natural gas line with an ISX15 G. The newest natural gas offering will be targeted towards heavy-duty, over-the-road customers.

The ISX15 G comes on the heels of the ISX12 G, which was recently announced and will begin production in 2013. The ISX12 G tops out at 400 hp and 1,450 lb.-ft. of torque, which Cummins acknowledged isn’t sufficient for some customers, including those in Canada that regularly traverse the Rocky Mountains.

“We know we have customers today that would like to have more horsepower and more torque in a natural gas over-the-road engine,” acknowledged Ed Pence, general manager of the heavy-duty engine business.

The engine will enter the field-testing phase in early 2013, Pence said, and will be in full production by 2015.