Tanks are the same between 959 and V2...supposedly.
According to a revzilla article:
Mechanically, much of the V2 is the same as the outgoing 959. The aluminum monocoque “frame” that reaches from the top of the engine forward to the headstock is the same piece, for example, as is the majority of the trellis rear subframe. Suspension components are identical to the 959, though they are tuned slightly softer. The fuel tank is the same, and many of the engine’s parts have been reused (the displacement remains 955 cc). Broadly, the updates to the 959 platform to create the Panigale V2 focused on squeezing five more horsepower out of the mill (for a claimed total of 155) while rising to Euro-5 emissions standards, evolving the suite of electronic rider aids, and adapting the Panigale V4 aesthetic to the V2
