Well we all know the metroliner EMU and DMU failed but what made Amtrak want to use the desighn for it's passenger fleet?

The Amfleet carbodies are very light and incredibly strong. The Amfleet car also has Budd Pioneer III trucks which are also very light and very reliable.

Some 51 years later, many of the Metroliner coaches are still in service as cab cars. The difficulty was the complex propulsion equipment with small orders (30 and 31 cars each) from two vendors and no real prototype. (The DOT test cars T-1 to T-4 used Budd Pioneer III trucks which were much lighter than the GSC outside-equalizer trucks used on the Metroliners, which made the latter much heavier thus requiring different propulsion gear.)

The SPV-2000's were the DMU version of the Amfleet, but they, too had reliability issues.

The Amfleet cars are a huge success; they had some issues with cold weather at first, but those were resolved other than snow accumulating in the door pockets. Built to replace 80 MPH cars in the NEC, they were approved for 125 MPH as soon as track conditions and AEM-7 motors made those speeds possible.

Phil Mulligan