Although the game is already out and it did not get very impressive review scores, Warner Bros and Avalanche Studios have now released official 4K resolution screenshots from the game.
While it did not get impressive review scores from usual gaming sites, scoring 8.4 from IGN, 4/5 at GamesRadar, 5/10 on Polygon and 6 on Gamespot, the game runs perfectly on the PC. There aren't a lot of reviews online since most sites were busy with Metal Gear Solid V: The Phantom Pain, which might be another reason why it got such low scores.
Based on the new Avalanche Engine, Mad Max does not look half bad at 4K resolution as you can see from screenshots below.
The game was released yesterday, and it is available on PC, Playstation 4 and Xbox One.