The fickle winter weather might prove a key factor in New Zealand's round of the FIA World Rally Championship that begins in Hamilton tomorrow.

Finland's Marcus Gronholm comes into the 11th round of the World Championship in New Zealand leading defending champion Sebastien Loeb by just eight points.

Gronholm (Ford) will be first away in Friday's five special stages in the Otorohanga - Waitomo region before returning for the super stage in Mystery Creek near Hamilton.

If the weather stays fine then he will have the unenviable task of sweeping the heavy gravel off the fast and flowing roads which will prove an impediment to his chances on the opening day.

However should it rain during the event then Gronholm may hold an advantage of better conditions before the roads cut up for drivers further down the order.

Loeb (Citroen), the two-time World Champion, knows he has some barriers in the way if he is to close the gap on Gronholm.  He did not compete last year as he was recovering from a broken collarbone, and was restricted to taking part in reconnaissance only.

"I am disadvantaged a bit that I only did the reconnaissance last year because the stages were new last year and I don't have a lot of experience.  I hope it won't be a big disadvantage and I can fight for the victory," Loeb said.

The Citroen driver faces Gronholm on his favourite gravel surfaces.  The Finn has won four times at Rally New Zealand and a victory this weekend will make him the most successful driver in the history of the event, going past the four wins by Carlos Sainz.

"I know that Marcus in New Zealand is really fast so it will not be easy to win here.  It's one of my favourite rallies but I know Marcus has won a lot of times here."

Gronholm greatly enjoys New Zealand and is looking forward to growing his lead in the Championship with three of the last five events on Loeb's favoured tarmac surface.

"Eight points lead in the Championship is not so many.  So my aim is to go all out for the win here, and of course we cannot make a mistake," Gronholm said.

"I like the roads here.  They are a lot like we have at home in Finland, and that has always made it very enjoyable here in New Zealand."

The Ford driver may find his teammate Mikko Hirvonen may also push him after they finished 1-2 in the last gravel rally in Finland.

Hirvonen is currently third in the Championship and only nine points behind Loeb.

"I am very happy with how the car is performing right now.  It is not possible I think to catch Sebastien if he finishes all the rallies," Hirvonen said.

"But I really like New Zealand, it is one of my favourite rallies and the roads are very much like home in Finland, without the big jumps.  So we will be pushing as fast as we can."

This trio are favoured for the podium although former world champion Petter Solberg, who has had problems with his Subaru, will be a crowd favourite with his electric driving style.

There will be plenty of interest in the Production Car World Rally Championship where Japan's Toshi Arai and his New Zealand co-driver Toni Sircombe have a handy 14 point lead.

There are three New Zealanders competing in the PWRC led by National Champion Richard Mason (Subaru), who was second in the PWRC and 10th overall in a five-year-old car last year.  His aim is to win the class in the hope that it will help his plan to find the $1 million funding to compete in the PWRC next year.

The two guest entries went to Dunedin's Emma Gilmour, who has a new car after a spectacular crash in Whangarei in May.  She will be joined by young South Canterbury driver Hayden Paddon, who became the youngest driver to win a round of the New Zealand Rally Championship when he took out Rally Whangarei, which doubled as the Asia Pacific Rally Championship event.

Rally New Zealand starts with the traditional shakedown test at Mystery Creek this morning ahead of the Ceremonial Start in Hood Street, Hamilton this evening.

The rally proper begins on Friday with four stages in the Otorohanga and Waitomo region before returning for the Super Stage at Mystery Creek.  Day two involves five stages in the Franklin District and northern Waikato with a further Super Stage, with the final day in Raglan with six special stages finishing with the Super Stage at the Rally Headquarters and Service Park at Mystery Creek.