yeah what nismo said is all true . i usually let it sit particulary on a cold mornin for about 30 seconds , drive it slowly tring to keep the revs under 2000 . then after about 5 mins i look at all my guages especially oil an then go for it but 5mins is generally all u need no need to idle for that long a period , it would be a waste same with cooling if ive been thrashin it all the way home
then the TT takes longer, but if i say drive (normally) for a few mins after then it doesnt take long at all , and i think is better for the engine then rather switching it just off