CARB Aims to Require Truck, Engine Makers to Extend Emissions Warranties

engines emissions
California Air Resources Board

California environmental officials are working on a plan to require truck and engine manufacturers to extend emissions system warranties up to more than four times longer than current regulations require.

The proposal calls for the California Air Resources Board in December to approve requirements for manufacturers to extend vehicle and engine emissions warranties for new compression-ignition Class 8 vehicles sold in the state to 10 years/435,000 miles/22,000 hours compared with current terms of 5 years/100,000 miles/3,000 hours.

Under the proposal, Class 6 and Class 7 truck emissions warranties also would be extended to 10 years/185,000 miles and Class 4 and Class 5 trucks to 10 years/110,000 miles.

CARB said it seeks to extend the warranty period because the current warranty period “does not reflect real-world longevity and because longer warranty periods would result in lower NOx emissions.”



“Class 8 heavy-duty vehicles frequently operate upwards of a million miles before a major overhaul is needed, but they are required to be warranted for only 100,000 miles under CARB and U.S. EPA regulation,” CARB said in a document outlining the proposal. “With longer required warranty periods, manufacturers would need to design more durable emissions control systems and components.”

The requirement also would result in a more timely repair of malfunctioning emissions-related components that heavy truck owners otherwise would not fix if they had to pay out-of-pocket, CARB said.

The proposal, scheduled for CARB board consideration in December, is designed to ensure that in-use heavy-duty vehicles “continue to operate at their cleanest possible level.”

If the proposal is approved by the CARB board by year’s end, the new warranty requirements could be adopted in 2019 and implemented in 2024, according to CARB.

CARB has scheduled a workshop on the issue for July 12 at 10 a.m. Pacific Daylight Time at the South Coast Air Quality Management District in Diamond Bar, Calif. The workshop also will be streamed online.

The requirement is part of the state’s sustainable freight program intended to reduce toxic diesel emissions, said Mike Tunnell, director of environmental research for American Trucking Associations.

“The way CARB views it is they intend to extend the performance of these systems,” Tunnell said. “The question is, how much do you pay for these systems?”

Tunnell added, “Who it will impact most are California truck dealerships because they will likely have to sell their trucks at a higher price than in other parts of the country to compensate for this additional warranty cost.”

Tunnell said ATA has not yet taken a position on the issue.

CARB has been studying the warranty issue for some time.

“Recent and ongoing CARB studies have identified numerous heavy-duty vehicles with mileages within their applicable useful-life periods but beyond their warranty period that have oxides of nitrogen emission levels significantly above their applicable certification standards,” the agency said. “Also, recent CARB reviews of manufacturer warranty claims show high warranty claim rates for both diesel- and natural gas-fueled heavy-duty vehicles.”

Interviews with fleets, retrofit installers and equipment dealers confirm these findings and suggest that some fleets are experiencing significant vehicle downtime, the agency said.

The trade groups Motor & Equipment Manufacturers Association and American Truck Dealers declined comment.