Those might be real numbers for those cars they tested against, but i would hardly consider that a sample of the sports cars on the market today.
15.25 is not too shabby for a quartermile for that jeep though.
But the mitsubshi evo 8 and the subaru wrx sti are both sub 14 seconds in the quarter mile. And 0-60 times for a good number of sports cars are sub 6 seconds.
Personally, my mr2 does 0-60 in 6.2 seconds, 1/4 in 14.7 seconds and has a 110 ft 60-0 in breaking (i don't know how that converts in to 70-0 though). That is in stock trim, 2.0L turbo charged engine at 9-11 lbs of boost with about 160 hp at the rear wheels.
So I think it is a fair test, but the opponents were chosen for a reason.