"We've still got some work to do, that's the bottom line."
Mason, who will as usual have wife Sara in the co-driver's seat, has little first-hand experience of the Gisborne roads but expects they will be similar to those in the Rally of Wairarapa.
"From what I can make out the surface and camber will be pretty much the same but the corners could be a bit tighter ... I'm pretty comfortable we'll be able to handle it okay."
As to tactics, Mason could be forgiven for taking a more conservative approach than usual considering he just has to finish to take the national title but while he won't be taking any undue risks he is aiming to win the round as well as the overall championship.
"Motorsport is all about going fast and I'd like to think we will still be faster than anyone else," he said.
"If the car is running smoothly we will be having a decent crack at it, we won't be holding back."