A new study finds the Montreal's Grand Prix isn't as beneficial to the economy as once believed.

The province previously pegged economic spinoffs from the race at $90 million dollars.

The study instead shows the race adds $42 million to the local economy and supports the equivalent of 640 full-time jobs.

Governments will take in $8.1 million in GST, PST and income taxes from the event, despite the fact that the three levels of government pay more than $18 million per year to host it.

“I always had an idea that they were somewhat overvalued and this confirms it,” said economist Pierre Emmanuel Paradis.

The latest report is incomplete, said Emmanuel, because it doesn't take into account all the side activities that go along with the race, including the drivers’ dinner and the fashion show.

“In terms of, is it really a great deal for the government, we don’t quite have the answer,” he said.

Montreal Mayor Denis Coderre said there are other intangibles to having Montreal showcased on the world stage.

“People know there's a soul in Montreal, there's a joie de vivre, there’s a reason to come because it’s going to be fun, you're going to eat well, people are warm,” he said.

“It’s the tourism event par excellence in Quebec and Canada,” said Tourism Minister Julie Boulet, adding that the province make money on it last year.

The government signed a deal two years ago that will see the race stay in Montreal until at least 2024.