I'd have to so no... the 16-710G3B had slightly higher BSFC than the orignal 16-710G3 (both at 3800hp ratings), and T2 emission standards supposedly increased BSFC as well.
That seems a little counter productive doesn't it? I would assume that the emissions improvments were a significant enough improvement that the loss of efficency was offset. At least as far as Exhaust is concerned. Even so, it would have to be lower than the 16-645.