Heavy rain and standing water in the Wairarapa could make conditions treacherous for drivers this weekend at the final round of the New Zealand Rally Championship.

Rotorua’s Dean Sumner holds a healthy 29-point lead from Emma Gilmour but knows that one slip-up could see it all wash away.

“We’re going to Wairarapa to win the championship,” Sumner said. “But at the same time, we know we have to minimise risk and keep the car on the road.”

Dunlop motorsport manager Richard Fraser says the rally route will differ from previous years, with new East Coast stages chosen to avoid farms in the midst of lambing.

“The rally usually has a lot of loose gravel on the road but with the recent wet weather, reports are that the surface is very muddy in places,” he said.

“We’ve had quite a few enquiries about the new medium-compound RW-spec DZ86 tyre. These tyres have a slightly wider groove and four extra block cuts to provide more bite in wet, muddy conditions.

“Anticipating cool morning temperatures, a few drivers are also looking at the soft-compound, regular DZ86 tyre,” Richard added.

A total of nine national championship class trophies are waiting to be claimed in Masterton, making this weekend ‘the one to watch’.

Along with the main field, 17 classic rally machines will line up as part of the inaugural Malcolm Stewart Classic Rally; including two-time Dunlop International Classic Rally of Otago winner Derek Ayson.

Trusthouse Racetech Rally Wairarapa kicks off with a ceremonial start and NZRC signing session 6pm on Friday night at Masterton’s Copthorne Resort, before the championship fight takes to the roads at 8am on Saturday morning.