"For a national rally the format doesn't work as well but we've stayed committed to running the rally as we originally planned it because Tauranga has been good to us and it's important to train our staff and volunteer officials so they are ready to stage a WRC event in the future."
Johnston said a Tauranga-based rally would only run again in 2018 if New Zealand is successful in gaining a place on the 2019 WRC calendar.
This month's two-day rally will be the final round of the New Zealand Rally Championship and also revives the Rally of New Zealand title last used for the 2011 WRC event.
A 54-crew entry list is headed by Kiwi WRC star Hayden Paddon driving his AP4 specification Hyundai i20 and also features the national title contenders as well as international flavour with three crews from Japan and a New Caledonian team.
Looking ahead to 2018 the Tauranga event isn't included on the NZ Rally Championship calendar that was released earlier this week.
The Otago, Whangarei, Canterbury and Coromandel events remain part of the national championship while a new winter event based in Timaru is an addition to the series.
The recent Waitomo Rally won't run again next year while plans to use the Raglan and Te Akau stages are provisionally part of a Hamilton-based final round in October.