It is a 2016 treatment, which also requires a new gearbox. In this drawing we can see that on the 2015 engine the oil tank has been moved from the back of the engine to the front (red arrows). The new unit will also have the MGU-K removed from the back to the lower-left side of the block (blue arrows), like all the other manufacturers do.

The objective is to make a narrower rear end to the car for aerodynamic reasons. The suggestion is that Kimi Raikkonen, who is not in championship contention, will use the new unit at the next round in the United States and then Ferrari can test and develop it in the final four races of the season.