Mercedes boss, Toto Wolff admits concern over how Ferrari is constantly introducing upgrades without exceeding spending limits.

Thus far, the Maranello outfit has been one of the busiest teams in terms of bringing upgrades to each race, even if in Austria it wishes it hadn't.

But in the eyes of Toto Wolff it isn't the constant updates to the SF-26, including the new engine introduced in Austria, but the sheer cost, and whether it breaks the rules.

"We're a little bit surprised that Ferrari can throw these huge updates at the car in the way they do," he told reporters in the aftermath of Sunday's race.

"In my opinion, they need to be running out of money soon, cost cap money, because we can't do that," he admitted. "We're simply lacking the buffer in the cost cap to be able to bring so many parts in the way they do.

"So, hopefully that's going to change towards the end of the season when they won't be able to bring any parts anymore. At least, let's say, the logic would say that and we're going to come with more."

Almost every race has witnessed an upgrade from the Italian team, and while there were the major upgrades in Miami and Spain, there have been endless revisions to the car ever since Melbourne.

Benefitting from the controversial ADUO system, which will see Red Bull Powertrains rivals allowed extra cash for upgrading purposes, Ferrari, like Audi, has already spent it in its efforts to overhaul Mercedes.

By contrast, the German team has been quite frugal in its spending - then again it started with the best overall package - while the likes of Aston Martin, aware of the dud it has on its hands, has barely opened its wallet.

"The only ones who are not slowing down are Ferrari," said Wolff. "You can see we had one big upgrade that we introduced in Montreal and small parts that come in between.

"I think the same for Red Bull and McLaren," he continued. "It's just Ferrari seems to be limitless in that way, and then on top, they were expecting an ADUO and come with a new engine.

So, they must have started development six months ago."

Expect Woody to express similar concerns in 3.. 2.. 1..