SACE | Southern Alliance for Clean Energy

Retrofit Your Current Vehicle


There are several upgrades that can be installed on your vehicle that will result in more mileage, better performance, and fewer emissions. All vehicle maintenance and service should be performed by or under the supervision of a trained automotive technician.

Installing Pollution Control Technology (diesel only): Retrofitting a vehicle is one of the most effective ways to reduce pollution from both on road and non-road vehicles. Retrofitting can include the repowering or rebuilding of an engine, but most commonly refers to the use of pollution control technologies (retrofits) to reduce harmful emissions.

Below is a list of retrofits currently available. Most of the retrofits should only be run with Ultra-Low Sulfur Diesel Fuel (ULSD). ULSD is currently available nationally as of Fall 2006. The availability of ULSD will enable these technologies to be installed on existing engines and begin reducing harmful pollutants from diesel exhaust today.

Crankcase Filter (CCF): Crankcase filters are places at the blow-by valve of a diesel engine. The filters capture the crankcase emissions and filters out the oil. The oil is placed back in the oil pan and the remaining exhaust is sent to the tailpipe. The use of a crankcase filter significantly reduces PM emissions inside the vehicle. The core filters must be replaced yearly. The estimate cost is $700 with 100% at engine emission reduction.

Diesel Oxidation Catalyst (DOC): This is a replacement for the muffler of a vehicle. It is made with a catalyzed ceramic flow-through core that removes particulate matter and hydrocarbons from the exhaust stream. These filters do not require ultra low sulfur diesel (ULSD) fuel to perform at peak efficiency. They also do not require maintenance once installed. They are guaranteed to work for the lifetime of the bus. The estimated cost is $2000 with a PM reduction of 20-40%, HC 90%, and CO 90%.

Catalyzed Wire Mesh Filters (CWMF): CWMFs are the newest form of emissions reduction devices. They are a blend of DOCs and diesel particulate filters. Like the DOCs, CWMFs ar a replacement for the muffle. The CWMFs contain a wire mesh core that traps PM, HC, and CO. They have efficiencies approaching that of a DPF. The heat from the exhaust converts the pollutants into carbon dioxide, water vapor, and ash. CWMFs do not require ULSD or maintenance.

Diesel Particulate Filter (DPF): DPFs reduce the highest amount of emissions from a vehicle. However, they are also the most sensitive of the emissions control technologoies. They require ULSD and exhaust temperatures of 220 to 240 degrees Celsius over defined periods of the operating cycle. They also require yearly maintenance in the form of cleaning the core filter. The filter consists of catalyzed ceramic core with forced flow channels that can become plugged by ash if not cleaned properly. EPA standards require 2007 and newer diesel vehicles to feature factory-installed CCFs and DPFs. The estimated cost is $7500 and reduces PM by 80-90%, HC 50-90%, and CO 50-90%.

*information provided from Diesel Engine Retrofit Fact Sheet by the Environmental Protection Agency

Upgrading the Ignition System: Upgrading a vehicle to a higher-output ignition system results in more efficient combustion of fuel within the engine. This includes upgrading the ignition coil to a high-output model, upgrading spark-plug wires to a high performance model, and upgrading spark-plugs to a high-output series.

Upgrading the Air Filter: An older air filter can prevent the flow of air to the engine of a vehicle. There are several high-flow air filters on the market that provide better air flow to the engine, resulting in substantial mileage increases with little hassle.

Upgrading Vehicle Aerodynamics: The aerodynamics of a vehicle refer to the amount of air resistance caused by the vehicle’s shape and contour. By installing more aerodynamic body components on the vehicle, the amount of drag, or air resistance, will be reduced, resulting in better fuel economy. Front and rear spoilers, vent covers, and fuel canards are a few examples of universal aerodynamic body components that can installed on a vehicle.

60+ Vehicle Modifications for Better Fuel Economy

For more information on retrofits and retrofit programs, check out the following websites:
(Compiled by SACE from Clean Air Task Force and U.S. EPA Data)