And here is that literature on coolant/antifreeze longevity:
Nissan TSB # NTB09-04a
or Infiniti TSB # ITB09-029a
1. Blue coolant
Long life stuff, it comes in newer models from the factory.
Nissan sources mention that from the factory, it will last 10 years/135,000 miles. Elsewhere it also says that from the factory it is good for 7 years/105,000 miles.
However, if you flushed and filled with this coolant as a service, it is good for 5 years/75,000 miles
2. Green coolant
Nissan alludes to a life of 4 years/60,000 miles
3. Mixture of Blue + Green coolants
Will result in the mixture taking the shorter life of 4 years/60,000 miles
Take all those numbers as you will, but what is certain is that coolant needs to be changed at some point, just like engine oil. Also, I personally would go conservative and change it more frequently.