SpaceX Announces Attempt to Send Dragon Capsule to Mars as Early as 2018

Planning to send Dragon to Mars as soon as 2018. Red Dragons will inform overall Mars architecture, details to come

link.

Speculation:

They will do this either in 2018 or 2021.

The reason being they will want to take advantage of the free return trajectories that Inspiration Mars identified.

This will require a FalconHeavy because the F9 doesn't have the umph.