Control of Air Pollution; Amendments to Emission Requirements Applicable to New Nonroad Compression-Ignition Engines at or Above 37 Kilowatts: Provisions for Replacement Compression-Ignition Engines and the Use of On-Highway Compression-Ignition Engines in Nonroad Vehicles

This rulemaking amends the regulations applicable to compression-ignition nonroad engines at or above 37 kilowatts (kW) to address two disruptive situations that have arisen regarding the implementation of regulations applicable to these nonroad engines. No air quality impact is expected from these amendments. These amendments will allow nonroad vehicle manufacturers to use certified on-highway engines in nonroad vehicles that are constructed from on-highway vehicles or that must use public roads between job sites. These amendments also will allow engine manufacturers to provide uncertified replacement engines to repower pre-regulation nonroad equipment when that equipment experiences major engine failure.