Mario Kart: Double Dash!! has a total of 21 karts to choose from. They rank in either Light, Medium, or Heavy class (excluding the Parade Kart, which is open to all characters) and are rated for speed, acceleration, and weight. Below is a guide to the karts and their ranks and ratings.
Red Fire
The Red Fire is an all-around good choice for any track and is average in rating. That's the way Mario prefers his karts, and yet he still wins.
Green Fire
Heart Coach
The Heart Coach is good to use for tracks with long straightaways and tight curves. It is generally a good kart for staying up with the other racers. It also captures Peach's sense of style.
Bloom Coach
The Bloom Coach is similar to the Heart Coach, only it is lighter and slightly faster. It works at top performance on a track with wide roads and curves that aren't too tight. It is nearly average in rating. Daisy liked Peach's kart so much that she made her own version of it.
Turbo Yoshi
Turbo Birdo
Goo-Goo Buggy
The Goo-Goo Buggy is a good kart for wide courses because they give the kart a good driving space. The reason it needs the space is because it is a very light kart and can easily be thrown off of narrow tracks by the heavy weights. Another thing to point out is that it has a very poor speed. The best thing, however, is that it has almost the best acceleration of any karts. To make it faster, have Baby Mario or Baby Luigi as part of the team manning it so their Chain Chomp will send it speeding!
Rattle Buggy
The Rattle Buggy is almost exactly like the Goo-Goo Buggy, only it has a better top speed. However, this makes its acceleration less as fast than the Goo-Goo Buggy. It has a very low weight equal to the Goo-Goo Buggy's, so use it on wide tracks. It also works fantastic with the Chain Chomp!
Toad Kart
The Toad Kart is a great kart for just about any track. It may have the same rating as the Rattle Buggy, but it has better stability on the track, making it harder to bump around. It has great acceleration to help it get back up to speed if it crashes.
Toadette Kart
The Toadette Kart has a better acceleration than the Toad Kart, which makes it better at recovering from an accident. It may be slower than the Toad Kart, but it functions just as well. It has good stability and doesn't go far after a bump from another heavier kart because of it. It is good to use on any track.
Koopa Dasher
The Koopa Dasher is a slower but quick-recovering kart. It has a great acceleration for trouble on the track and has an aerodynamic shell design Koopa and Paratroopa agreed on. It may be light, but it packs a strong punch on the field.
Para Wing
The Para Wing has a low maximum speed but it is the most aerodynamic kart on the field. After Koopa and Paratroopa made the Koopa Dasher, they made the Para Wing. It is just as light as the Koopa Dasher and is the fastest-accelerating kart of all the karts. The reason it is the most aerodynamic kart is because Paratroopa put a personal finishing touch on it: Wings!
DK Jumbo
Barrel Train
The Barrel Train is good for any track. It has a fantastic top speed and enough weight to throw other racers around, but what's really special about it is that it's not just a kart, but a train! The only issue is getting this kart up to speed, so keep your Mushrooms handy!
Koopa King
Bullet Blaster
The Bullet Blast is a impressively fast kart. It has an acceleration high enough to reach top speed quickly and take turns well. The only problem is, it's the lightest kart on the field! It gets bumped around the easiest, so avoid encountering heaver karts. This kart should be used for wider tracks and is great on sharp curves.
Wario Car
Waluigi Racer
Piranha Pipes
The Piranha Pipes is a kart that is fantastic for pushing around other racers. It works great on tracks with long, wide turns. The only drawback for speed and weight is its acceleration, which makes it pretty lousy on tracks with many sharp curves. However, a track with many boost pads remedies this.
Boo Pipes
The Boo Pipes is a reverse of the Piranha Pipes kart because it sacrifices speed for acceleration. Unlike the Piranha Pipes, the Boo Pipes is great at holding its own on a track with many curves. Because it has great acceleration, it can easily get back up to speed. It is also the same weight as the Piranha Pipes. The only issue is its low speed. Using it on a long track will help to gain a better lead over the other racers.
Parade Kart
The Parade Kart is the last kart to choose from. It is Toadsworth's gift to you after completing the Mirror Mode All Cup Tour. It has good acceleration, a great top speed, and enough weight to knock around other racers. It also can accompany any character in any weight class. Best of all, it comes with two detachable parade crowns so everyone can watch the winners of the Mario Kart Grand Prix go by. This golden kart is best for any track.