And one last question regarding time. Can someone please explain how the tach differs from the hobbs by a factor of 1.1 to 1.2, I understand that the hobbs is off the master and the tach is off oil pressure (which would give a very slight time difference when starting and shutting down) but am I correct in saying the engine has to be above a certain rpm or producing a certain HP for the tach to engage and start counting, if so is the tach so sensitive it can detect the oil pressure difference between an engine taxiing/idling at 1000-1200 rpm and economy cruise at 2300 rpm,
Also does the tach not count/run below a certain rpm threshold or does it count/run at a slower rate until it hits a certain rpm or oil pressure that then triggers it to count the hours at the same rate as the hobbs does ?