Engine wear and longevity

[novadude]

Direct fuel injection..... have taken most of the cold start wear.

I really wonder about this one, as I suspect it may be a step backwards for cold start wear. It would seem that it may be better to inject the fuel upstream when cold to allow vacuum to help vaporize the fuel. I would suspect that you get an awful lot of liquid fuel and incomplete burn with GDI when the engine is very cold. I only say this because I've noticed an awful lot of tailpipe soot on 3 GDI engines I've had in daily drivers (Mine and my wife's). Much more soot than you'd see with port injection.