"Overall the figures aren't too bad but let's just hope the spectator numbers don't fall away over the coming years like they did in Hamilton," Mr Brewer said.
"All the promised economic return of this five-year event is predicated on attendee numbers holding very strong, and so here's hoping theydo."
The crowd of 117,167 that attended over the three days of racing was smaller than the 130,000 the organisers had hoped for - and marginally above the 116,698 who attended the last year of racing in Hamilton in 2012.
Visitor nights to the city, which Mayor Len Brown estimated at about 50,000 when he spoke in support of the event's return to Auckland, came in at 36,883.
Even so, figures supplied by Covec suggest the event generated $7.5 million for the region's economy - above the $7.068 million targeted.
"The big focus for us is that new money coming into Auckland, and to exceed that GDP target is enormous for us," Ateed manager major events Jennah Wootten said. "It's year two of the major events strategy being in place and we've smashed our targets once again. And it was a huge start to our five-year partnership with V8s out at Puke, so we are very happy."
Mr Brewer said the fact spectator numbers dropped off from 170,000 in the first year at Hamilton in 2008 to just 105,432 in 2011 suggested the Pukekohe event could struggle to retain strong attendance numbers.
The use of public transport for the event had been much lower than projected and visitor nights were well down on what was promised, he said.
"A majority of Auckland councillors signed off on $10.6 million of ratepayers' money on the promise of $7 million in extra annual economic benefit, 130,000 spectators, over 50,000 visitor nights, and a strong uptake of public transport," he said.
"Here's hoping there's no further slippage in spectator numbers."