The G37 coupe is about 100 lbs heavier than the G35/G37 sedan; hard to believe but true because the coupe's larger doors require more reinforcement to achieve a high side-impact crash rating.
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2008 Infiniti G37 Sport - Road Test/2008 New Car Reviews/Car Shopping/Hot Lists/Reviews/Car and Driver - Car And Driver ).
G37 coupe's 0-60 times and 1/4 times are pretty much identical to the 07/08 G35 sedan times. The 09 G37 sedan is faster than the G37 coupe. It will be interesting to see what kind of specs Nissan releases for the 370Z and then also what kind of results all the mags get when they test it...