I have a 2007 model and have the same issue.
I complained to the Nissan agent, and they told me that the capacity is around 70 litres for the standard versions.

They told me that they leave a large reserve capacity in case of emergency and that you can do over 45km when the tank flashes empty without a problem.

To be honest, I once made a risk and drove around 60km after the tank flashed empty and was able to fill around 67 litres (I paid 54 QR for Super Gasoline).

So I guess they were right.

Inside Doha, I do around 300km to 320km for full tank with about 30-40km after tank flashes empty.

Combined on high ways and in Doha (2-3 days a week on highways), I get around 340-360km for full tank with about 30-40km after tank flashes empty.

The Agent said that on highways, the Pathfinder should achieve 380km with a full tank.

One last issue:

I get a bumpy noise from the steering when I go over rough land as if the steering were loose.
When I complained about this, they told me that this was normal in all Pathfinder models!

Does this happen to you too?