According to Nintendo’s financial results for the second quarter of the fiscal year ending in March 2022, Mario Kart 8 Deluxe has sold 38.74 million copies on Nintendo Switch.
Mario Kart 8 originally was released in May 2014 for Wii U but eventually was ported over to Nintendo Switch as Mario Kart 8 Deluxe in April 2017.
It has now surpassed the lifetime sales of Mario Kart Wii, which is at 37.38 million copies.
It’s tough to say because Mario Kart 8 Deluxe on Nintendo Switch keeps selling gangbusters.