I let mine idle about one minute or long enough to be firing on all cylinders since I have a bad GP. Like others have said it's best to drive off gently immediately after startup. The engine will surely warm up much quicker that way. I maintain a limit of 2000 RPM while traversing the neighborhood then limit it to 2500 RPM after entering the main road.

The thing with idling is this: Combustion temps are so low at idle that hardly any heat is imparted to the block. EGT's are 200deg or less and combustion effeciency is at it's lowest. Unburned fuel vapor mixes with carbon and exhaust gasses and cruds up the exhaust valves and emission control circuits. Over time, this can lead to poor performance and even sticking valves which may come in contact with the pistons. This condition is known as "wet stacking".

Oh, and I hope you guys are joking about the starting fluid... You like your pre-chambers right?

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250