Engine Upgrade & Conversion Kits

Man working on an engine.Engine upgrade and conversion kits lower air emissions and fuel consumption. Kits are available for on-road and off-road vehicles, off-road equipment, marine vessels, and locomotives. Only EPA or CARB-certified engine upgrade and conversion kits can be legally installed on existing engines.

Engine Upgrade Kits

An engine upgrade kit is most commonly installed on equipment that has a long lifespan. It involves removing parts of an old, polluting diesel engine and replacing them with new parts that reduce diesel emissions, improve diagnostic and display capabilities, lower vibration and noise levels, and provide smoother overall operation and significant fuel savings. The U.S. Environmental Protection Agency currently requires upgrades as part of engine overhauls for applicable locomotive and marine engines, per the Inland Marine and Locomotive Rule.


  • Reduces diesel emissions (certified kits reduce diesel particulate matter by at least 25%)
  • Reduces other criteria pollutant emissions and greenhouse gases
  • Reduces diesel fuel consumption by 1.5 to 3%
  • Reduces lube oil consumption by 25 to 30%
  • Improves diagnostic and display capabilities
  • Lowers vibration and noise levels
  • Is more cost effective for equipment with long lifespans than complete engine or vehicle/vessel replacement (typical payback period for certified kits is 3 to 6 years, depending on fuel consumption)

Conversion Kits

Conversion kits help clean the air by modifying diesel-fueled (or gasoline-fueled) vehicles and engines to use an alternative, cleaner fuel, such as natural gas, propane, alcohols, electricity, or a blend of conventional and alternative fuels. Clean, alternative fuels provide vehicle owners with new fuel supply choices and solutions to concerns about fuel costs, energy security, and emissions. We recommend an EPA-certified conversion kit to avoid violating the law that prohibits tampering with the vehicle’s original engine and increasing emissions. Find more information on EPA-certified conversion kits and alternative fuels by visiting the EPA website.


  • Reduces diesel emissions (amount depends on conversion type)
  • Reduces greenhouse gases (amount depends on conversion type)
  • Lowers fuel costs (amount depends on conversion type)
  • Reduces dependence on foreign fuels