The difference is that the g93 has more torque overall, and faster access to both it's power and torque over the g92. The g92's power and torque are peaking at 7k rpm as opposed to 5.5-6k rpm in the g93. Of course the g92 will rev out for longer but the g93 also has around 8k rpm to play with, and make more power more consistently as a daily driver (won't have to flog it all the time to get all of it's power out). It also has 200cc of displacement over the g92. For power... g92 NA over g93 NA, g93t over g92t. Same with mods really. For optimal results you would put the g92 head on a g93 block to have 1.8L mivec and the best of both worlds. Fuel-wise, who gives a flying fark.