Is it really necessary to run a diesel SUV with turbo to run in idle for a minute at least before starting the journey and at the end before switching the ignition off...
Dear Castaway,
It is required to idle before stopping only if you have been ripping off the car before stoppping, ripping would mean crossing 3.5K RPM, for an Diesel car. Normally,it is required to cool the intercooler as when turbo kicks in it revs at very high RPMS to push the circulated exhaust gases. so to subside it is recommended to idle car before stopping. If you have been doing a sedate drive before stopping like upto 1500 RPMs or so, the turbo would not have kicked in so you can normally shut it down.
Regarding Idling on start, I would recommend to idle any car for atleast 30 Secs or so be a Petrol OR Diesel if you are starting it after a gap of more that 5-6 Hrs, like after office and early mornings.
Turbo vehicles needs to be idled more, as the engine becomes warm and the exhaust gases are then forced in to kick in the turbo.
Hope it helps.
Cheers !!
SG