U.S. EPA Urges OEMs to Give Diesel Engines More Time to get Fixed Before Curtailing Performance

The United States Environmental Protection Agency (EPA) has issued new guidance to on-road and off-road vehicle diesel-powered vehicle manufacturers that will give drivers more time to get their engines fixed.

Since 2010, the EPA has required the use of diesel exhaust fluid for diesel vehicles to combat smog. When the vehicle needs to be replenished with diesel exhaust fluid, the vehicle must limit itself to specified low speeds, torque, and other engine performance metrics until the diesel exhaust fluid is applied. Faulty sensors can sometimes determine mistakenly that diesel exhaust fluid is needed, leading to vehicles being limited to speeds as low as 5 miles per hour.

An EPA regulation issued in 2022 will require OEMs to give diesel vehicle owners time to fix these sensors before the limitations on engine performance kick in, starting in 2027. The EPA's recent guidance asks OEMs to implement this change immediately by modifying vehicles that have yet-to-be sold and issuing software updates for those currently in use. For pickups and light-duty vehicles, the guidance calls for an 80 hour or 4,200 mile grace period before limiting the vehicle to 45 mph.

Click here to read the EPA's revised guidance in its entirety.