Its probably because the 2.0 has a smaller stroke and it can spin faster. T he 2.3 is 90*90mm while the 2.0 is 90*78. I think they bored it out some t oo so instead of being like 1995cc, its 20??. But it still makes 750HP and since it has AWD, it does 0-60 in like 2.3 sec. But its gearing limits it to only 155mph