The boss of V8 Supercars Australia says Pukekohe Park is the only viable option to keep the motoring event in New Zealand.
"It's black and white. If we couldn't have made Pukekohe work that would have been game over and we would shut the gate in New Zealand," Tony Cochrane said.
Strong lobbying to move the event to Hampton Downs in Waikato has been taking place since Auckland councillors voted 10 days ago to spend $10.6 million to ensure the return of the annual event to Pukekohe.
Three councillors opposed to the expenditure have visited the two race tracks and declared Hampton Downs to be a better site and Waikato leaders have asked Auckland Mayor Len Brown why $6.6 million is being spent upgrading Pukekohe Park.
Mr Brown said the decision to go with Pukekohe Park was made by V8 Supercars Australia, which will own and underwrite the event from April next year for five years.
Mr Cochrane said there were several reasons for choosing the Pukekohe track.
The event needed to be as close as possible to Auckland to provide several thousand hotel beds and as close as possible to Auckland Airport to save transport costs.
Two 747 freight planes loaded with equipment for the event would be landing at the airport.
"Unfortunately Hampton Downs is not a viable proposition because of the [current] resource consent," he said.
"Hampton Downs still needs a lot of work to make it viable for a championship round of the V8s."
He acknowledged Pukekohe Park was in a "rundown, derelict state", but said by the time of the first event in April next year it would be a "magnificent facility right on the doorstep of Auckland, which has got to be great for New Zealand motorsport".
One of the difficulties for Hampton Downs - on 162ha of rural land 60km south of Auckland and 65km north of Hamilton - is getting resource consent to increase spectator numbers from 20,000 to 50,000 to stage events the size of the V8s.
The Waikato regional director of the Transport Agency, Harry Wilson, said the agency had concerns about the capacity to get large volumes of traffic off State Highway 1 to Hampton Downs.
Mr Wilson said that the agency was working with the owners of Hampton Downs to develop a traffic management strategy to enable large number of motor racing fans to safely access the raceway with a minimum effect on drivers using State Highway 1.
He hoped an agreement could be reached as part of the resource consent application.