Barrel Train

The Barrel Train is Diddy Kong's lightweight kart in Mario Kart: Double Dash!!, and it also appears as an unlockable kart body in Mario Kart 7. The Mario Kart 7 incarnation of the Barrel Train also appears as a trophy in Super Smash Bros. for Nintendo 3DS, driven by Donkey Kong.

Mario Kart: Double Dash!!
The Barrel Train is unlocked by completing the Star Cup in 150cc. Its nitrous comes from the horn, which makes the sound of a train whistle when speed boosting. Like any steam engine, the Barrel Train's exhaust pipe is a smokestack. It resembles the train from Kalimari Desert as well as the K64 from Paper Mario.

The Barrel Train is the heaviest lightweight kart in the game; its weight is tied with the Red Fire and Heart Coach karts, which are middleweight. It is also the only lightweight kart that can push around the middleweight Green Fire and Bloom Coach karts. According to the game status, it is tied with the Bullet Blaster as the fastest lightweight kart. However it also has the weakest acceleration of its weight class.

Although the game shows a four star speed stat, the Barrel Train's top speed is tied with that of the Bullet Blaster, DK Jumbo, and Piranha Pipes, and its small size enables it to avoid most hazards more easily. It also has the weakest traction of all karts, as it still maintains its speed briefly after getting hit by the Lightning item. However, while it has a two star acceleration stat, the Barrel Train accelerates slower than the Green Fire, but it does accelerate better than all the other two star acceleration karts. Finally, the Barrel Train is one of the two four star speed karts to lose the least amount of speed upon going off-road, with the other being the Piranha Pipes.

The Barrel Train's small size, weak traction, and high top speed make it a popular choice for getting good times in the Time Trials game mode.

This kart is also one of the four karts to have stats "out of the ordinary" for its weight class, with the others being the Green Fire, the Boo Pipes, and the Turbo Birdo.

Mario Kart 7
The Barrel Train appears again in the Nintendo 3DS title, Mario Kart 7. Here, its kart body appears as a retro, customizable kart body. The main difference is that it can be ridden by anyone - not only small but also medium and large-sized characters - and it no longer has the green platform, and only contains 4 wheels, thus eliminating the second racer, and making the kart only for one racer. The star emblem on the front is also removed, filled in by the selected character's logo.

The Barrel Train offers a small speed and weight boost, while hindering handling. In fact, it is tied with the Bumble V and Bruiser for having the lowest handling of all kart bodies. In terms of its hidden stats, the Barrel Train offers one of the highest mini-turbo boosts (tied with the Bumble V and Koopa Clown), but it also has the lowest sea speed of all kart bodies.

Mario Kart: Double Dash!!

 * Speed [[File:Gold star.png]][[File:Gold star.png]][[File:Gold star.png]][[File:Gold star.png]]
 * Acceleration [[File:Gold star.png]][[File:Gold star.png]]
 * Weight [[File:Gold star.png]][[File:Gold star.png]][[File:Gold star.png]]

Mario Kart 7

 * Speed: +0.25
 * Sea Speed: -0.75
 * Air Speed: -0.25
 * Acceleration: 0
 * Weight: +0.25
 * Handling: -0.5
 * Sea Handling: 0
 * Air Handling: 0
 * Off-Road: 0
 * Mini-Turbo: +1.5
 * Stability: 0
 * Drift: -0.25

Trivia

 * A train that resembles the Barrel Train can be seen buried in Gritzy Desert during the (past) events of Mario & Luigi: Partners in Time.
 * The train whistle that the horn makes is the same as the train from Animal Crossing.
 * In Mario Kart: Double Dash!!, the Barrel Train, Koopa King, Bullet Blaster, DK Jumbo and the Parade Kart are the only karts in the game with unique engine sounds.