The United States Postal Service mail-delivery fleet could transition to all-electric trucks with an $8 billion provision recently advanced by a House of Representatives committee, Bloomberg reported last week.

The House Oversight and Reform Committee added the language to a bill aimed at better tracking mailed ballots before approving the bill and sending it to the full House for consideration, according to the report.

In February, the Postal Service announced a $6 billion contract with Oshkosh Defense for new mail trucks, but said only 10% will be electric.

The contract calls for Oshkosh to deliver between 55,000 and 165,000 vehicles over 10 years, starting in 2023. Most of those vehicles will be built with internal-combustion engines, but can be retrofitted with electric powertrains in the future, the Postal Service said at the time.

USPS Next Generation Delivery Vehicle - Oshkosh Defense

USPS Next Generation Delivery Vehicle - Oshkosh Defense

While new mail trucks are desperately needed to replace the Postal Service's fleet of decades-old vehicles, the plan is not in agreement with President Biden's proposal earlier this year to make the entire federal vehicle fleet electric. Given their long anticipated lifespans, these mail trucks could be producing tailpipe emissions for many years before their converted to electric power—a process that could also prove expensive and impractical.

That disparity quickly drew criticism from lawmakers. Democrats in the House proposed legislation March requiring a higher number of zero-emission vehicles from the start.

The Postal Service began soliciting bids to replace its LLV (Long Life Vehicle) mail trucks, which date back to the 1980s, in 2016. Groups have been lobbying for electric mail trucks almost as long.

In 2017, 13 groups signed a letter urging the Postal Service to choose an electrified option. At the time, Workhose/Hackney was proposing a range-extended electric powertrain, while Mahindra pitched a mild-hybrid powertrain.