Mario Kart 8 has sold 5.59 million units as of November 21st, 2015 (according to vgchartz, the actual number is probably higher)

Super Mario Kart has sold 8.76 million units lifetime.

So there are let's say 3 million units left (maybe even less)

The game has incredible legs. In the week ending November 21st it has sold 103k units. That's almost as much as Rise of the Tomb Raider (Xbox One) in its second week and Assassin's Creed Syndicate (PS4) in its fifth week. 

I expect the game to sell similiar numbers in the remaining weeks of this year. In 2016 it will also sell good and the holiday season of 2016 it will sell similiar to 2015's. In the end it could reach 8.76 million units. 

Wii U also has amazing attach rates. Let's say Wii U has sold 15 million units at the end of next year. Then there are probably ~8 million Mario Kart 8 owners. Not that much left to 8.76 million.

What do you say? Is it possible?

EDIT: maybe I should add that this includes both physical and digital copies of the game.

I expect it to sell right around Double Dash's numbers. I don't think Super Mario Kart's numbers are really possible.

Wii U's lifetime is nearing its end, i think, maybe 1-2 years? the game itself i doubt it would sell another 3 million even until 5 years. As NX is approaching and a new MK series would come, MK 8 won't be near SMK numbers. unless Nintendo drop the price to $20 or less.

Does the launch of a new console mean that the game doesn't sell anymore? Obviously not. Mario Kart Wii still sells.

I can also see a "Nintendo Select" for $24.99 of something like that.

I predict it will end up around 7.4-7.8 million.
It will beat Double Dash, but beating Super Mario Kart is a little bit too much.

7m including digital

Nah, the NX announcement will significantly reduce Wii U sales, and with them the MK8 copies bundled with them. Don't worry, MK8 already did an amazing job on such an unlucky platform, there's no shame in stopping at around 6.5Mil ...

Yeah it'll most likely outsell it.

A little off topic, anyone see those amazing Splatoon legs? Holy shit. :D

Actually Nintendo official numbers are saying that MK8 on September 30 was at 5.87m. MK8 LT will probably be around 8m if count WiiU LT around 15m.

I think it will end up selling somewhere between Double Dash and Super Mario Kart.