Low Emission
Idle Systems



Benefits of LEI Systems

  • Reduces visible emissions
    (unburned hydrocarbons and particulate material) during idle and other low load conditions.
  • Economical
  • Durable, low maintenance.
  • Automated operation requires no user input.
  • Simple installation fits to existing engine without alteration.

 What is Low Emission Idle (LEI)?

Engenious™ Engineering’s patented Low Emissions Idle (LEI) system is supplementary hardware designed to fit EMD engines to reduce smoke under low load conditions. LEI is an electronically controlled linkage that powers left and right cylinder banks alternately while the engine runs at lowest speeds. The system improves fuel burning efficiency and significantly reduces unburned hydrocarbons and exhaust opacity.

Compatible with any standard EMD diesel engine, as well as General Electric’s FDL series engines, LEI is a very quick, practical, and economical way for you to reduce visible emissions in switch yards as well as in long haul service.

How Does Low Emission Idle Work?

Low Emission Idle (LEI) is an alternating bank idle system. LEI runs the engine on half of its cylinders when the engine is operating in modes of low engine specific power output (at idle or low RPM). The additional load the non-firing cylinders place on the engine cause the firing cylinders to burn diesel fuel more efficiently. This results in fuel savings, and a significant reduction in the level of unburned hydrocarbons and the emission opacity in the exhaust. Cleaner exhaust is also apparent when throttling up after extended periods of idling, a result of cleaner and more complete combustion at idle. When the LEI system is active, a slight momentary drop in engine speed is detectable when the engine changes operational banks. The frequency of the bank to bank operation change is adjustable ranging from every 15 seconds to every 4 minutes.

The LEI system disables instantly when the control inputs change to another operation mode and returns the engine to normal operation.

Contact Us


6411 Pacific Hwy. East Tacoma, WA 98484

(253) 312-7888

(253) 922-2258