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The weight of each character has little effect in and of itself, but will affect the types of vehicle available to the player.

Unlockables

In order to unlock characters via Time Trials, you must also restart the game in order for it to take effect.

There are 3 ways to unlock most characters, but you only have to do one of them.

Character	Weight	Ways to unlock
Baby Daisy	Lightweight	Get a 1 Star Rank for all 50cc Wii Cups. Play against Peach 20 times. Play 1,950 races.
Baby Luigi	Lightweight	Unlock 8 Expert Staff Ghosts. Win 100 Wi-Fi Ghost Races. Play 3,150 races.
Baby Mario	Lightweight	N/A
Baby Peach	Lightweight	N/A
Birdo	Middleweight	Beat 250 people while playing online. Play on 16 courses in Time Trials.
Bowser	Heavyweight	N/A
Bowser Jr.	Middleweight	Attain at least 1 Star Rank for all 100cc Retro Cups. Play 3,450 races.
Daisy	Middleweight	Attain a Gold Trophy in 150cc Special Cup. Play 2,850 races.
Diddy Kong	Middleweight	Attain Gold Trophies in all 50cc Cups. Play 450 races.
Donkey Kong	Heavyweight	N/A
Dry Bones	Lightweight	Get 1st place in the 100cc Leaf Cup. Play 1,050 races.
Dry Bowser	Heavyweight	Attain at least a 1-Star Rank in all 150cc Nitro Grand Prix Cups. Play 4,350 races.
Funky Kong	Heavyweight	Unlock 4 Fast Staff Ghost Data in Time Trials. Win 25 Wi-Fi Ghost Races. Play 2,250 races.
King Boo	Heavyweight	Attain a Gold Trophy in 50cc Star Cup. Play 750 races.
Koopa Troopa	Lightweight	N/A
Luigi	Middleweight	N/A
Mario	Middleweight	N/A
Mii (Outfit A)	??	Attain a Gold Trophy at 100cc Special Cup. Play 1,650 races.
Mii (Outfit B)	??	Unlock all Expert Staff Ghost Data in Time Trials. Win 5,000 Wi-Fi Ghost Races. Play 5,100 races.
Peach	Middleweight	N/A
Rosalina[1]	Heavyweight	Have a Super Mario Galaxy save on your Wii, then win 50 races. Get a 1 Star Rank for all 150cc Mirror Grand Prix cups. Play 4,950 races.
Toad	Lightweight	N/A
Toadette	Lightweight	Play on all 32 courses in Time Trials. Win 1,000 Wi-Fi races. Play 3,150 races.
Waluigi	Heavyweight	N/A
Wario	Heavyweight	N/A
Yoshi	Middleweight	N/A

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