I always thought that Mario Kart games were developed using the same pieces as old Mario Kart games, but interestingly whenever a new Mario Kart game is being developed it always start from scratch. Nintendo doesn’t reuse its programming, assets, or other material across entries in the series.
We know this thanks to a Mario Kart 8 interview with director Kosuke Yabuki recently conducted by EDGE. The magazine mentioned that vehicles are easy to handle once acclimatized to, but wondered if Yabuki ever worried about the possibility of making the game less immediate.
He said in response:
This time around, we really did add in a lot of new elements, but we also aimed to do away with explanations or tutorials as much as possible. The Mario Kart series cherishes both depth and breadth of gameplay; it’s broadly accessible and anyone can pick up a controller and start playing, but at the same time the games are also deep enough that players can achieve greater results through practice. Each time we make a Mario Kart, we make everything from scratch: programming, graphics and even the audio. Even if we’re making something similar to what was used in a previous title, it will be different because of the person doing it. We think this subtle change is crucial.
Well this is certainly interesting information, in a lot of ways I thought pieces of programming was taken between games because of how similar some characters looked or even how similar courses look from the original to the new version. But it seems that no matter how similar they look the courses are redone and this just shows how great the game developers at Nintendo are. Overall it is just an interesting set of trivia.
Source: Nintendo Everything