my TT is set to automattically set a time from anywhere of 10 secs to 10 mins. My car on the average idles somewhere between 17 and 55 seconds after driving it and getting off the freeway only a mile and a half from home. It just depends on what kind of mood I'm in when I'm sitting at the light to the main street.

The point of a TT is to let the oil cool down instead of turning the engine off at a high temp. and clogging the oil line and building up in the turbo.