I suspect the GT-R is chosen because it makes for an interesting comparison (website hits). It has been seen as something of a giant-killer, having beaten various Porsches, Corvettes, Lambos, etc, over the past few years. Now comes along a killer of the giant-killer. And it's something Autocar have done before:
I can fully believe weight is a factor. Here's my theory. One of Mizuno's claims is that the GT-R is purposefully heavy to simulate the kind of downforce that he thinks is appropriate for that level of performance; I don't fully believe this explanation, and think that it probably has more to do with keeping the costs down. But he does bring up a good point, as it relates to tire dynamics and wet conditions. Like most any car, the GT-R's suspension is adjustable, and in various markets comes delivered in any of 3 basic settings: road, fast road (performance), and track. In the US many owners have complained of too-aggressive camber that quickly wears out the inside shoulders. The point of having negative camber is to keep the contact patch square to the road during hard cornering. This offers more grip than a straight 0-degree camber setup (where the car tends to "roll over" on its outside tire edge) and better manages the heat, distributing it more evenly across the surface of the tire. Thus, the mass of the car is pressed firmly into the pavement and the huge outer treadblocks are called into play to generate enormous grip.
But this is the theory in the dry. In the wet, a GT-R with that same camber is less able to achieve the roll angle that would allow it to make full use of its huge outer treadblocks, which might be moot with regard to hydroplaning anyway. The mass that had before been exploiting gravity's normal (perpendicular) force to maintain grip, now seeing that coefficient of friction greatly diminished, then has a greater propensity to push wide (horizontal direction) due to centrifugal force.
Chris Harris noted this in his GT2 vs GT-R comparo on the Nurburgring. The GT-R, which could summon seemingly magical levels of grip in the dry, struggled greatly in cold/damp conditions compared to the lighter GT2, which also benefitted from more weight over the driven wheels.
The takeaway is that under certain conditions, hight levels of power and hp/wt ratios won't account for as much as we might think. Wet conditions and a tight/road track can bring out giant-killer killers, as the weaker, smaller car can exploit more of its power more of the time. An A1 Quattro driver probably can wring more out from the Audi than a GT-R driver can on a tight, wet road.
, P Zero Corsa struggles on the wet even more than the Dunlops...
