MEMPHIS, Tenn. — Cummins Inc. announced its complete product lineup for the school bus market at the National Association for Pupil Transportation trade show on Tuesday.

Officials said these diesel and natural gas engines are designed to meet the 2014 U.S. EPA greenhouse gas (GHG) and fuel-efficiency standards a full year early.

New regulations from the EPA and the U.S. Department of Transportation will institute equivalent carbon dioxide and fuel-efficiency standards for commercial vehicle engines beginning in 2014. All of Cummins' on-highway products will meet these standards Jan. 1, 2013.

"Cummins continues to show customers our commitment to being better where it counts for their business,” said Tom Hodek, general manager, North American bus business. “We are delivering products with better fuel economy, reliability and durability that, in turn, will meet the 2014 GHG and fuel-efficiency standards a year early. This pioneering capability as a leader in diesel engine technology emphasizes our longstanding commitment to bring cleaner and more fuel efficient products to the market for our customers."

For 2013, Cummins will offer the school bus market two diesel-powered engines — the ISB6.7 and ISL9.

The ISB6.7 is driven by the High Pressure Common Rail fuel system, VGT turbocharger and fully integrated electronic controls. The 2013 ISL9 features the XPI fuel system to maximize fuel economy and performance while decreasing exhaust emissions to near-zero levels.

The ISB6.7 has ratings of 200 hp to 300 hp (149-224 kW), and the ISL9 has ratings of 260 hp to 370 hp (194-276 kW). Both engines also feature the Cummins Aftertreatment System from Cummins Emission Solutions, which integrates a diesel particulate filter and selective catalytic reduction.

Officials said onboard diagnostics (OBD) will be included on the diesel engine lineup for 2013 as well. OBD monitors emissions-related engine systems and components, and alerts the operator of any malfunctions. OBD is designed to further enhance the engine and operating system by providing early detection of emissions-related faults.

The 2013 Cummins Westport ISL G natural gas engine will remain in the Cummins product portfolio for the school bus market. The spark-ignited ISL G, which shares 80% of common components with its diesel counterpart, the ISL9, delivers low-end torque, transient response and quiet operation, according to the company. It also features a passive Three-Way Catalyst aftertreatment system, which is maintenance-free and packaged as a part of the muffler.

Cummins said it will offer a base warranty, with new 10-year extended coverage options available.