Early and Later Year VG30DE Engine Differences

[GerryO]

Can anyone list or direct me to a summary of the mechanical differences between the early and later year J30 engine?

Maintenance costs for the later year engine are lower; why? A Kevlar timing belt? It also appears that some hose connection have been relocated to on top of the plenum for easier access.

How interchangeable would complete plenums be?

Is performance better, especially in terms of gas mileage?

Thanks, Gerry

[Bernie (NoVA)]

The plenum casting didn't change - fittings can be removed & swapped.