The vast preponderance of experienced/commercial pilots do them on the run
Try that in the RAAF and you would quite rightly be court-martialled for reckless and unprofessional behaviour. While I realise that in GA money is perceived as far more important than the tenets of good airmanship, the risks involved with stuffing around with run-ups during the taxiing are not worth the insurance penalty if you make a hash of things while concentrating on an instrument needle when you should be watching where you are going.
This business of a pilot rushing around just because it is a GA aircraft reminds me of a classic example of piss-poor airmanship at Essendon years ago. The RFDS Chieftain this bloke was taxiing had a 137 page roller-blind checklist installed on the coaming. It began with "Gidday." It was night time and raining and as the pilot was manoeuvering out of the RFDS lines he was busy scrolling through his checklist and was quite surprised when his wing tip clobbered another Chieftain. There was no fuss and bother from the chief pilot after all it was "just GA" and these little things happen sometimes.
Funny thing was, when the airlines had piston engines you never ever saw a DC4, DC3, Convair, Connies et al doing their engine run-ups while taxiing. The captain would have faced disciplinary action and even termination of employment.
As far as flying schools waiting for the oil temp to get into the green range before run, that is no more than a money making exercise. Certainly in the Lycomings in Cessna's in cold weather, the POH advises that the oil temp might not even register on the gauge until the aircraft is airborne. So yet another GA myth is destroyed but still the bogans of this industry believe them.
