A logical point of reference for Mario Kart 8's sales is the previous Mario Kart games.
Mario Kart 7 and Mario Kart 8launched during the holiday season, which makes things a little tricky. We can try to adjust for that by simply ignoring the first 6 weeks of sales. If we do that, we get the following situation.
| After 6 weeks | After 20 weeks | Sales in those 14 weeks | Expected lifetime (7) or actual lifetime(Wii/DS) | |
| Mario Kart DS | 2362k | 3674k | 1312k | 22947k |
| Mario Kart Wii | 4580k | 7070k | 2490k | 34652k |
| Mario Kart 7 | 4181k | 5295k | 1114k | ~ 13000k |
| Mario Kart 8 (lacking digital) | 2033k | 2743k | 710k |
So, Mario Kart DS sold 5.7% of its sales in those 14 weeks (which are January-April)
Mario Kart Wii sold 7.2% of its total sales in those 14 weeks (June to September)
Mario Kart 7 looks to have sold around 8.56% of its total sales in those 14 weeks.
In order for Mario Kart 8 to fail to outsell Super Circuit, it will need to have sold more than 13% of its sales in those 14 weeks. With digital sales included, it's likely somewhere around 15%.
In other words, Mario Kart 8 would need absolutely atrocious legs compared to the other games in the series, relative to its sales from week 6 to 20. There is no genuinely good reason for this to be the case.
Which means that the chances of Mario Kart 8 failing to outsell Super Circuit are extremely slim.
