From the Super Mario Wiki
As its name implies, the kart is a gold-painted version of the respective games' Standard Kart. In both games, CPU players never use the Gold Standard, along with the Gold Tires, and the Gold Glider, making this body player-exclusive. When this body is combined with the Gold Tires and Gold Glider, they complete the whole Gold Standard kart.
Mario Kart 7
In Mario Kart 7, the Gold Standard can be unlocked by earning 10000 VR in Wi-Fi races, or alternatively, by collecting 20,000 coins.
The Gold Standard gives a slight boost in speed and weight, but slightly hinders the acceleration and off-road stats, making it the polar opposite of the Pipe Frame in a way. However, its hidden stats are affected differently than those of the Pipe Frame, as it slightly hinders air speed and drift.
In this game, when all gold parts are combined, the Gold Standard gives great speed (the second strongest boost in the game) and has good weight, but hinders air speed, and acceleration, noticeably hinders sea speed, land, and air handling. The combined Gold Standard has poor drifting and the worst off-road in the game.
Mario Kart 8 / Mario Kart 8 Deluxe
The Gold Standard returns in Mario Kart 8 and Mario Kart 8 Deluxe, where it has received a small detail change: instead of the character's emblem, the Gold Standard's logo is a number 8 from the game's logo with a wreath of olive leaves around it. This kart and the GLA are the only kart bodies that do not display the characters' emblems. It is unlocked in Mario Kart 8 by getting a star rank on every GP cup for every engine class, and in Mario Kart 8 Deluxe by getting a star rank on every GP cup in Mirror mode.
In Mario Kart 8, the Gold Standard offers a strong boost in ground speed and a slight boost in weight, but slightly hinders acceleration and highly hinders traction. In terms of its hidden stats, it also boosts speed on every terrain, but hinders anti-gravity handling and mini-turbo. It shares its stats with the Mach 8, Circuit Special, Sports Coupe, B Dasher, and P-Wing vehicle bodies. When all gold parts are combined, it boosts speed on all terrains (except water), along with weight, but hinders anti-gravity handling, acceleration, mini-turbo, and traction.
In Mario Kart 8 Deluxe, the Gold Standard's stats have been altered; it now only slightly boosts ground speed, while no longer boosting speed in any other terrain, but rather worsening water speed, as well as no longer boosting weight. Additionally, acceleration is hindered further, while air handling is now hindered instead of anti-gravity handling. Also, the traction and mini-turbo stats are not hindered as much as previously. The Gold Standard shares its stats with the Sneeker and Master Cycle. When all gold parts are combined, the Gold Standard is considerably worse than in Mario Kart 8, as while it still increases ground speed and weight, it now hinders every other stat with the exception of anti-gravity speed and water handling; it especially hinders acceleration, air handling, anti-gravity handling, traction, and mini-turbo, all in a heavy way.
Mario Kart Tour
The Gold Standard returns in Mario Kart Tour, retaining most of its design from Mario Kart 8 and Mario Kart 8 Deluxe, but with the "8" emblem being replaced by the respective character's own emblem. It is only available for use in the Coin Rush mode. It uses the Gold Tires.
Mario Kart 7
Mario Kart 8
Mario Kart 8 Deluxe
Names in other languages