Leak Down Procedure (Pic Heavy)

So how much difference will there be (avg) in hot vs cold? I ask because my very fresh & very strong running 273 with no oil usage whatso ever cold has rite @ 20% (cold). I checked it only to compare with my 60 hp mercury outboard as a "new motor"base line. Out board (cold) was the same 20% using the matco dual gauge set up in carcraft mentioned above. Is there that much diffrence hot vs cold? The 273 runs flawless plenty of power no oil usage at all & keeps oil clean.