Mercedes motorsport boss Toto Wolff has revealed the team lost almost half a second in lap time on the straights alone compared to Ferrari at the German Grand Prix, as new questions surrounding the Scuderia's engine are raised.

This season, the Italian team has emerged as the new benchmark in terms of engine performance, ending the Brackley-based outfit's domination in this area. The reason for that is believed to be a new split battery design which has led to big gains in the deployment of electrical power.

Around the time of the Monaco GP back in May, there were claims Ferrari had used this concept to cleverly exceed the permitted 120 kilowatts of power from the MGU-K, however, following investigations by the FIA, it was declared within the legal boundaries set by the governing body.

That appeared to satisfy the queries of Mercedes and Renault, with the matter going quiet, now though, new GPS data from the Austrian Grand Prix is suggesting a big increase in horsepower from the race at the Red Bull Ring.

According to German publication Auto Motor und Sport, the speed of the Ferrari down the straights would be equivalent to 28 kilowatts or 38 horsepower in gains, a figure, they suggest, manufacturers usually require two years to achieve.

A similar situation played out at Silverstone, with the Ferrari-powered cars benefitting from the ability to better harvest and then deploy electrical power on the straights on a layout where opportunities to recharge the battery are few.

Then, after qualifying at Hockenheim, Wolff revealed the additional power had proven the difference with around five-tenths deficit on the straights with Valtteri Bottas finishing just two-tenths behind pole-sitter Sebastian Vettel.

"They have a great power unit, huge performance," the Austrian said.

"We’re looking good through all kinds of corners but we are not able to match their straight-line performance."

Rather than renew questions over legality, which some are doing, the Mercedes chief instead called on his team at Brixworth to respond.

"Of course we didn't expect it but in Formula 1 you need to be ready for literally anything and we need to find out how we can increase our output," he said.

“There’s not one single second I want to look at Ferrari. I want to look at ourselves, I want to look at Mercedes and see how, is there anything we’ve missed.

"How can we increase our power output? On the ICE, on the electrical systems? From the battery, from the MGU-H – whatever we can look at because if we want to win this championship or stay in the hunt of the championship we’ve got a severe warning today, in terms of what we’ve seen," Toto added.

Considering where this possible gain has come from, many are pointing to the software with the team not introducing any new elements since the Canadian Grand Prix last month and their customers, Haas and Sauber, seeing similar gains.

That has led to Renault Sport managing director Cyril Abiteboul to call for a standard program to be introduced.

"That would rule out any suspicion," he said. "Unless you're able to tell clearly whether a technique is legal or not, you have to unify it."