Ef vs air nz website
 

Empty seats in EF doesn't align to unsold seats but rather the combination of unsold plus where someone hasn't allocated themself a seat yet.

There's no "vs" here... both of those sources are saying the same thing. C is the highest business class fare bucket, so that has 2 available (whereas there's one available in discount business class, ie D). Similarly, U is the highest premium economy fare bucket, with 3 seats available, while the cheaper PE fare buckets have fewer.

As for the seat map... that is only the most general of guides and really can't be counted on. It's not unusual for a few pax not to have allocated seats yet.

Just to clarify what mad_atta has already mentioned, you've misinterpreted the EF data. The numbers are not cumulative - U3 E2 O1 as an example means Air NZ have 3 PE seats left in total and and are willing to sell 1 as an O class fare, will sell 2 as an E class fare, but will happily sell the whole 3 as a U class fare.

In this situation if you do a search for a 1 PE seat it'll be at a cheaper O class, but if you search for 2 PE seats these will both be E class at a higher price. When you start booking last minute flights for 2 people and there is only limited availability (using this flight as a classic example) you can often make good savings if you book 2 individual tickets and then link the PNRs.

Thanks sbiddle for that clarification and explanation. Got a call at the gate for the upgrade. Interesting Id called the call centre to double check I didnt need a bag and the agent said if J not available they'd automatically consider PE without me having to ask

It's interesting to see that clearing single class upgrades automatically if a double upgrade isn't available seems to now be occurring as this didn't previously occur and you had to ask.

Yes. He also said for short haul PE-J Silver RU (didnt say their own or whether gifted) trump Elite SHRU RU/EAPD from Y to J.

ie all the PE-J upgrades considered above the double class upgrades.
didnt say whether this was the case for long haul or not.

He seemed to have a list of the pecking order of upgrades tho wouldn't read it out unfortunately.