4.5 PSD, wastegate or EGR

[50jd60]

About the new 4.5 PSD, have heard it has the wastegate instead of the EGR valve, is this true, if so why would Ford go back to the wastegate system.

[CanadaGuy]

It uses both. A cooled EGR system similar to that of the 6.0, and a twin-turbo set up with a waste-gate that by-passes the primary turbo and directs exhaust into the secondary turbo when boost gets too high.

I'd imagine they've gone back to the waste-gate system because of all the problems with the VGT system... it works great in theory, but has been quite troublesome in reality. The turbo on the 4.5 is similar (if not the same) as the turbo that will be on the 6.4.