The Budd Metroliner was a class of American electric multiple unit (EMU) railcar designed for first-class, high-speed service between New York City and Washington, D.C., on the Northeast Corridor.

After difficulties testing the cars, PRR successor Penn Central began its eponymous Metroliner service on January 16, 1969.

On August 9, 1965, with the High Speed Ground Transportation Act of 1965 pending, representatives from the Pennsylvania Railroad (PRR), the United States Department of Transportation (DOT), and a private consulting firm began setting specifications for an electric multiple unit high speed passenger train.

[4]: 32 On May 6, 1966, the High Speed Ground Transportation project ordered 50 railcars from the Budd Company, with delivery beginning in September 1967.

[4]: 14  On August 30, 1966, Governor William Scranton of Pennsylvania announced plans to purchase 11 additional railcars for upgraded 80 mph (130 km/h) PRR regional service between Philadelphia and Harrisburg.

[4]: 36 The ancestor of the Metroliner multiple unit railcar was the Budd Pioneer III which had been developed for the Pennsylvania Railroad in 1958 as a new concept in long distance passenger service in the east.

After a fleet of 55 improved Pioneer III cars referred to as Silverliners were ordered for commuter trains in the Philadelphia area, the United States Department of Transportation placed a follow-up order for 4 Silverliners, specially modified for high speed operation on the PRR's Northeast Corridor.

Equipped with several modifications, including a semi-streamlined slab end on the front of the lead car, the experimental train ran a series of test runs, reaching a speed of 156 miles per hour (251 km/h) on April 2, 1967.

After multiple failures of the control and propulsion systems at just 70 mph (110 km/h), PRR executives pushed for the beginning of service to be delayed.

[6]: 38 [5] On December 17, 1967, tests of Metroliners passing older MP54 railcars caused windows to be ripped out of the MP54s due to the pressure drop, indicating that the high-speed rolling stock might not mix well with legacy equipment.

The remainder of the cars were delivered with Penn Central logos, but retained the PRR-specified livery of gray paint with red pinstripes.

[7]: 10  The pantographs on the Westinghouse-powered cars would bounce on the aging catenary wires, then draw high currents due to improperly designed transformers.

Substation modifications later that month and a legal settlement between Budd and Penn Central in November paved the way for service to begin.

[8] Metroliner service finally started on January 16, 1969, with a single daily round trip leaving New York in the morning and Washington in the afternoon.

[10]: 16  Due to the condition of the track and signal system, the Federal Railroad Administration never allowed Metroliners to go faster than 120 mph (190 km/h) between Washington and New York.

They had worse acceleration than the Silverliners already in service, tended to overheat when making numerous closely spaced stops, and had difficulty climbing the grade out of Suburban Station.

[12] Out-of-service rates reached 40% and higher; In June, Senator Clifford Case of New Jersey began pushing the DOT to devote $5 million to the rebuild program to increase reliability.

[13] The DOT contracted with GE and Westinghouse in June for a R&D project of further electrical modifications, with detailed plans made in July.

[15]: 7, 11  In late April, Amtrak accepted six of the leased cars for revenue service, which permitted an increase to 14 round trips on May 1.

The dynamic braking resistors and the air intakes were relocated to a streamlined bump on the roof, reducing overheating and snow ingestion issues that had occurred when they were mounted under the carbody.

[21]: 42 On February 6, 1977, Amtrak announced plans to spend $24.4 million to overhaul all 61 cars as part of a larger fleet renewal program.

[23] Eight GG1s were regeared for 110 mph (180 km/h) to better meet Metroliner schedules, with the higher top speed balancing the locomotives' lower acceleration.

On April 30, 1978, schedules were lengthened to 3 hours 20 minutes as more Amfleet-based trains were used, and the name was modified to Metroliner Service to reflect the changing equipment.

[25]: 1  Some of these later rebuilt cars received the Phase II scheme, a red and blue front end with a large Amtrak logo across the full width.

[25]: 187  A wreck of the Washington-Boston Night Owl four days later in Chester, Pennsylvania took two AEM-7 locomotives out of commission, exacerbating a shortage of electric motive power available to Amtrak.

In the late 1980s Amtrak found itself with a supply of surplus Metroliner cars with problematic propulsion systems, but with sound body and frame, stored at their Wilmington and Bear shop complexes in Delaware.

Ten (9630–9639) were designated for West Coast routes including the San Diegan, six (9640–9645) for the Atlantic City Express, and seven (9646–9652) for Chicago-based regional services.

[1] After the Vermonter's backup move was eliminated in 2014, the ex-Metroliner cab cars have been used primarily on the Keystone Service, Valley Flyer and Amtrak Hartford Line.

After a yearlong refurbishment, it entered service in November 2000 as T-16 (DOTX 216), a research and track geometry car capable of measurements at up to 160 mph (260 km/h).

[29][1] One Metroliner snack bar car, #860, is preserved at the Railroad Museum of Pennsylvania in its original paint scheme and interior.