Spoken like a Mario Kart expert. It comes down to which you prefer. There also may be a difference in characters but I'm not giving anything away.

There is, let the noobz find it out them self and not rely on us(everyone who has a score above 9000and got there on pure skill) to tell them everything.

ps.                                                                                                                                                                                              stop picking luigi circuit, if thats the only track you can win go practice and come back once you master some real tracks.      

I'm with Karts for this. Except to open the damn Expert Time Trials, but whatever, for regular playing, karts > bikes.

its called mario kart not mario bike

I prefer bikes, I can drift a lot sharper using bikes. Hugging the corners perfectly and I find that the decreased size of the bike is a advantage at the start of the race. Although karts still seem a lot faster, I prefer short cutting though races anyway. Something easier with bikes.

I like the bikes for their light movement and the Karts for speed.

I am sure a poor player that I don't use the manual drift -- so the bikes extra boost does not help me. Anyway, I prefer karts ... it is Mario Kart. (I had been racing Medium, then had to go to large for my Mii and finally got a Star Rating!).

Mike from Morgantown