Wii Grumble Volcano

Grumble Volcano is the fourth and last course of the Star Cup in Mario Kart Wii. It takes place in a volcanic area covered with lava. The course features many jumps and moving platforms, as well as many sharp corners. At certain times, sections of the track will crumble away into the lava, making the road smaller and harder to drive around. The track's music is very similar to that of World 8 in New Super Mario Bros. It reappears in Mario Kart 8 and Mario Kart 8 Deluxe as the third course of the Lightning Cup.

Course layout
The course takes place inside and around a volcano surrounded by lava. ? Blocks and Brick Blocks are also found lodged in rocks as part of the scenery. At the beginning of the race, the track is straight. However, parts of this section will fall into the lava as the race progresses. Lava Geysers may also occasionally spout in these areas. The track then enters the volcano and makes a turn, which will also crumble as the race continues, before approaching a moving platform, which allows the player to perform a Trick. This leads into a tunnel with an upper route and lower route, both of which have Item Boxes, and they both curve right and then left before leaving the volcano and approaching a pair of moving platforms, which also allow the player to perform tricks.

After the platforms, there are two roads. The right path leads to a ramp with a Dash Panel on it, while the left leads to a path with Item Boxes. After the roads meet, there is falling volcanic debris that serves as an obstacle, bursting into flames upon impact with the ground. During this section, pieces of land will crumble and begin to sink into the lava. The path then splits again, with a Dash Panel and a ramp on the left and a normal path on the right. Once the paths meet, the player can encounter a small ramp.

After the ramp, the path splits again with the right path taking a lower route, and there is eventually a left turn to a pair of ramps. The left path leads to a higher route with a ramp with a Dash Panel. Both routes feature crumbling sections and pipes with Fire Snakes, as well as more falling volcanic debris. The routes then meet and approach the finish line for the next lap. After passing the finish line, crumbling pieces of land are more common than they were in the first lap.

Shortcuts

 * Near the starting line is a rock that can be reached with a mushroom and performing a wheelie at the starting line or by performing a trick off the ramp before the finish line in a direction towards the rock. Once on the rock, the course can be completed by driving around the rock. The player must be careful as the rock will start to crumble at 53 seconds, and sink at 1:05. This glitch was removed in Mario Kart 8 as it does not use the same checkpoint system to determine if the lap will count like Mario Kart Wii does; besides that, the slopes of the rock are so steep that players will simply slide off.
 * After the cave and past the moving platforms is a rock to the right side of the raised section of the track. In the Mario Kart Wii version, it is possible to drive on the rock formation by using a mushroom to reach the right side of the forked road. The rock will sink 1:35 seconds into the race; however, the player can still have Lakitu bring them to the right side of the fork with the use of a mushroom and a wheelie or well-timed hop if they hit the edge and fall into the lava.
 * The final turn along the right side of the fork features an outcropping of rock that can be jumped off of with the aid of Mushrooms - it can be done with a single one, but it is easier with two.

Tournaments
The first tournament of June 2009 took place at this course. Players competed in a time trial race, but they had to race the track backwards. To start the time trial, players received a set of Triple Mushrooms. This tournament was later repeated as the second tournament of May 2011, the second tournament of August 2012, and the first tournament of November 2013, though with a "Karts only" restriction.

Mario Kart 8 / Mario Kart 8 Deluxe
Grumble Volcano makes its classic course debut in Mario Kart 8 and Mario Kart 8 Deluxe as the third race of the Lightning Cup. The clouds in the sky appear to be more orange than purple as opposed to in the original version. The volcano that the players drive through as well as the volcanoes in the background now have lava running down them. The course itself maintains its layout from the original, though both the first platform after the cave and the jump from the uphill left path now have Glide Ramps. Additionally, near the end of the course, at the right side of the fork, a portion of rock that serves as a trickable ramp has been added, allowing for a shortcut. To accommodate this, an additional segment of the track has been added that meets up with the main route right before the finish line. In laps 1 and 2, there is a rock blocking the shortcut, but at the start of lap 3, it will sink into the lava, letting the player use it on lap 3. Volcanic debris falls more slowly than in the original course, the crumbling pieces of road crumble and sink much quicker (with an additional sinking piece of land added in the volcanic debris section of the course), and the starting banner has been changed, now resembling a slightly deteriorated structure with torches added and the modern Mario Kart logo. Similar to, , and , the music remains mostly unchanged, but the guitar and sitar have been updated and the mastering has been tweaked.

Mario Kart Wii

 * European website bio: "With deep lava awaiting anyone who strays off the track and flaming fireballs littering your path, Grumble Volcano will undo all your previous hard work in the Star Cup if you aren't at the top of your game."
 * Trading card bio: "The racing can really heat up when battling it out at Grumble Volcano. Lakitu is always busy fishing racers out of the lava beds that line this course. There are many opportunities for mishaps here so watch who you're bumping into. And be sure to watch out for the sections of track that fall away."

Mario Kart 8 Original Soundtrack liner notes
"This is a remastered version of the Mario Kart Wii track. With all its boiling lava and cracking, sinking surfaces, there's something slightly bleak and downbeat about this course. We wanted to get this across in the music, but without making the atmosphere too heavy."

Mario Kart 8 / Mario Kart 8 Deluxe

 * Bullet Bill Speed Trial (Signs)
 * Morton Construction (Signs)

Trivia

 * As of the Princess Tour, this is the only course in Mario Kart Wii's Star Cup to not appear in Mario Kart Tour.