Performance dynamometer, dispersion realistic VR6

Engine: AAA transmission: APB US model 125KW vehicle 1st hand (USA & BRD), ran at takeover 78mls. Everything overtaken, no defects, wear or error messages! Before installing the pre-tech should be measured. Today, DynoJet says 120KW. Basically, the opinion of series VR is somewhere between “never reach the factory specifications” until “scatter totally far, you don’t need any tuning anymore”… Well, for me it’s just a question of whether it makes sense to make a comparison test on a different test bench or to accept the -5KW?