vRS CR TDI

Not that its a problem but can anyone tell me why the engine revs at 900rpm when in neutral but moving, for example when you're just coming up to a red light and slip it our of gear near stopping.

However, once you've actually stopped, the revs go down to 650rpm?

Stick it in neutral whilst moving and see what I mean.

Whats the reason behind this feature?

Anti-stall ! Same on the PD170 engine as well.

Also applies in 2nd & 3rd gears. If you are careful with your clutch control the car will pull away from rest in 2nd or 3rd without you touching the throttle pedal or it stalling.

Nothing to do with ensuring an adequate vacuum for brake assistance is it? Once the car knows its stopped it can lower the idle as little/no assistance is required.

Might be wrong but it makes sense to me.

My old diesel Nissan used to do the same.