Crowdfunded racer Project Cars may not make it onto the Wii U after all.

UK developer Slightly Mad Studios has admitted it is struggling to get the game running well on Nintendo's console, and that it is hoping the Japanese company will announce new hardware at this year’s E3.

"At the moment we're running at about 23fps [at 720p] on the Wii U," studio boss Ian Bell said on the game's official forums.

"Honestly, unless we really cut the looks back I think we're looking to Nintendo's next console. We could reach a fairly solid 30fps but it might take a hell of a lot of work.

"On the other hand, about halfway through us finishing, Nintendo might announce a new console (I have zero knowledge on this BTW but I've heard 'rumours'). Our work might just be the best thing that ever hit that new console in the driving sim genre,” he added.

"So we're playing a waiting game at the moment and yes, economics do come in to it."

Nintendo president Satoru Iwata has repeatedly said that the company will not discuss the NX console at E3 this year.

Project Cars was originally due to release on PlayStation 3 and Xbox 360 as well, but those versions were abandoned in late 2013.