okay well from my experience with my old torana race car.... i was young and silly and i had a mate i had to impress so i started it and revved it pretty hard after a little while of idling... about 8k.... went for a spin and wemt to like 8.5k several times and when i put it back in the shed it was fine ... when we went to take it to the drags the next wekend it developed a very bad miss...we changed coild ,plugs,leads,everything......ended up been a broken valve spring......all brand new done like 5 hours on the dyno......was broken from it not been warm enough and the wire in the spring not been ductile(flexible) enough which cause it to break...personally i would rather letting it get to operating temp before driving....reason been that the oil may not be at full protection till operating temp but it has no load on it unlike driving the car......hence idling it will not stress anything till it warms up and you take off..... i alwats warm mine fully before driving.......