Z30 engine, manual, 2006 model
Been travelling around Australia, started in Canberra with a roof top tent and full length roof rack.
Got 850km on 100 litres.
Up in Qld, now getting 500km on 100 litres.
Have changed air cleaner, for a little gain.
Using Flashlube diesel conditioner for a little gain, less rattles.
My guess is that the intercooler or AFM are leaching air.
Air conditioner drains a lot more than it should.