...........I'm kinda stumped with the GTO that is currently on GT6, because despite being the same car as the Holden Monaro and with a fully tuned spec of over 920 bhp (compared to the Monaro's 780 ish) it is no quicker...very odd.
...........You are giving it too much thought, bud. It's PDI logic...nobody gets it unless you work for 'em....