How does Mario Kart Wii decide your rank letter (A, B, C, D, E, F) or star in a Cup that you raced?
There is no official information on what determines your rank. A good track time seems to matter the most, but many elements are speculated to also help:
- lowest possible race finish time
- amount of time spent in 1st place
- boosts from mini-turbo, beginning of race, tricks
- successful item attacks
- successful wheelies
- falling off track or being slowed down by offroad areas
- hitting walls or obstacles
Though these are not confirmed, they serve as good guidelines.
The short answer is that no one knows. Some sites on the Internet claim that it is based on how often you went off the track, but I think it is more likely based on simple time around the course. Since going off course slows you down, it would be easy to confuse the two.
My belief (completely unconfirmed) with regards to the one, two and three star rankings is that if you beat the required time, you get the stars based on how many laps you were the fastest kart on the track. So for the three star ranking, you would need to be the fastest kart the entire race. However, it is difficult to get any data to back my belief up, so I'm probably wrong...