METRO Magazine Logo
MenuMENU
SearchSEARCH

San Diego MTS Retires Last Diesel Buses, Expands Electric Fleet

Replacing the last diesel buses will be 24 compressed natural gas express commuter buses built by Motor Coach Industries.

by METRO Staff
March 2, 2021
San Diego MTS Retires Last Diesel Buses, Expands Electric Fleet

At the same time as retiring its diesel fleet, San Diego MTS is also added two GILLIG zero-emission battery electric buses, upping the agency’s total to eight.

Credit:

San Diego MTS

3 min to read


The San Diego Metropolitan Transit System (MTS) hit a major clean-air milestone: retiring the last of its diesel buses and adding two more electric buses to its fleet.

“MTS retiring the last of its diesel buses from its fixed-route fleet is a monumental leap forward in air quality,” said Nathan Fletcher, MTS Board chair and chair, San Diego County Board of Supervisors. “It represents our commitment to environmental justice, sustainability, air quality and to being one of the leaders nationally in achieving these ambitious environmental standards.”  

Ad Loading...

Replacing the last diesel buses will be 24 compressed natural gas (CNG) express commuter buses built by Motor Coach Industries (MCI).

“Not only do the new MCI CNG buses offer an improved riding experience for our customers, we get substantially better air quality results from them as well,” said Sharon Cooney, MTS CEO. “There will be a 100-percent reduction in particulate matter, and a 98-percent reduction in NOx emissions over the diesel counterparts.”

The new express commuter buses will offer 57 forward-facing seats, are designed for highway speeds, and offer touring class comfort and safety. The vehicles will operate out of MTS’ East County Division in El Cajon, serving passengers on the Rapid Express 280 (Escondido-Downtown San Diego) and Rapid Express 290 (Rancho Bernardo-Downtown San Diego).

“Today, we’re proud to support the San Diego MTS in achieving this low-emission milestone,” said Chris Stoddart, president, New Flyer and MCI. “MTS has long pioneered sustainable mobility, having been the first agency in America to adopt CNG into its fleet nearly 20 years ago.”

At the same time as retiring the diesel fleet, MTS also added two GILLIG zero-emission battery electric buses, upping the agency’s total to eight. MTS began its zero-emission bus pilot program in 2017, and intends to complete a full transition to 100% zero emissions fixed-route vehicles by 2040. The two California-made GILLIG buses are the first of seven to be delivered to MTS. GILLIG’s zero-emission battery-electric buses are equipped with the Cummins electrified powertrain and are supported by a nationwide service network. Built on GILLIG’s low floor platform, the buses ensure parts and training commonality with MTS’s existing GILLIG fleet. Equipped with six onboard batteries, each bus has a battery capacity of 444 kWh, providing an estimated range of 140 miles. The buses utilize energy recovered from a regenerative braking system and feature a direct-drive traction motor with peak torque of 3500 Nm (2,582 lbs.-ft.).

Ad Loading...

“We are excited to partner with the San Diego Metropolitan Transit System as they work towards their Innovative Clean Transit goal of a 100-percent zero-emission fleet by 2040,” said Bill Fay, GILLIG VP of sales. “The new battery-electric buses support MTS’s commitment to excellent service and cleaner air for the communities they serve, and GILLIG is proud to be a part of this step forward.”

More Zero Emissions

Cover photo for Part 2 with Cecil Blandon
Managementby Alex RomanApril 30, 2026

Bus Tech Talk: Part 2 with AC Transit’s Cecil Blandon

In Part 2 of a two-part conversation, AC Transit’s director of maintenance joins co-hosts Alex Roman and Mark Hollenbeck to discuss his maintenance team’s work with various types of vehicle, training, augmented reality, and more.

Read More →
A WMATA bus underneath a cherry blossom tree
Busby Alex RomanApril 24, 2026

Bus Coalition Leaders Push to Protect Transit Funding in Critical Reauthorization Year

Coalition leaders outline priorities for preserving bus funding, maintaining competitive grants, and ensuring flexibility for transit agencies nationwide.

Read More →
Cincinnati Metro's new battery-electric bus, which was unveiled on Earth Day
Zero Emissionsby StaffApril 23, 2026

Cincinnati Metro Goes Electric

Two battery-electric buses entered service on Earth Day, with four additional vehicles expected to join the fleet this summer. Seven more buses are planned for the end of 2027, bringing Metro’s total zero-emission fleet to 13.

Read More →
Ad Loading...
A blue and white graphic with text reading "2026 Earth Day: How Transit Agencies Celebrated Nationwide."
Zero Emissionsby Elora HaynesApril 23, 2026

Transit Agencies Mark 2026 Earth Day with Free Rides, Sustainability Initiatives

Agencies from California to New York offered fare-free rides, community cleanups, and new tools to showcase transit’s role in cutting emissions.

Read More →
A photo of a San Antonio VIA Metropolitan Transit zero-emission bus.
Busby Staff and News ReportsApril 20, 2026

Recovery and Risk Define the Transit Bus Market in 2025

A 5% rise in deliveries and a surge in zero-emission buses signaled progress in 2025, but high costs, long lead times, and shifting funding priorities continue to cloud the outlook.

Read More →
A California zero-emission Big Blue Bus parked outside a bus depot.
Zero Emissionsby StaffApril 13, 2026

California's Big Blue Bus Moves Closer to All-Electric Future with $56 Million Investment

The Santa Monica agency’s new charging infrastructure and fleet expansion aim to improve air quality, equity, and long-term system resilience.

Read More →
Ad Loading...
Cover Photo for Bus Tech Talk
ManagementApril 9, 2026

Bus Tech Talk: AC Transit’s Cecil Blandon on Leadership, Mentorship, and a Career in Transit

In Part 1, Blandon shares his journey from the U.S. Marines to a leadership role in public transit, along with insights on mentorship and professional growth within the industry.

Read More →
Opening art for Sustabinability Partners Q&A
Zero Emissionsby Alex RomanMarch 25, 2026

Inside EVaaS: A New Model for Airport Fleet Electrification

Sustainability Partners’ Arnold Albiar discusses how a service-based approach is helping airports and public agencies deploy and manage electric fleets more efficiently.

Read More →
Rows of MTA's Long Island Railroad (LIRR) commuter rail cars.

New York Awards $4.5M for Zero-Emission Microtransit and Bike Access Projects

NYSERDA funding will support electric microtransit and secure bike storage to improve first- and last-mile connections across downstate New York.

Read More →
Ad Loading...
Cover photo for METROspectives with The Bus Coalition
Busby Alex RomanMarch 13, 2026

Inside The Bus Coalition’s Push for Stronger Federal Transit Investment

In this conversation, TBC’s Executive Director Ed Redfern, President Corey Aldridge, and Washington Representative Joel Rubin outline the coalition’s key policy priorities, the challenges facing transit agencies, and how industry stakeholders can work together to strengthen the voice of bus transit at the federal level.

Read More →