'Lift and coast' has been in Formula 1 for decades - Nico Rosberg

The amount of fuel saving required by drivers was in the spotlight at the Canadian Grand Prix, because the Montreal track layout means fuel usage is high there.

But following claims there is too much fuel saving during grands prix at the moment, Rosberg pointed out in Austria on Thursday that is it nothing new.

"Lift and coast is the most efficient way to save fuel - they even did it in the 80s," said the Mercedes driver.

"I remember my Dad [Keke] doing it when he was racing with Alain Prost at McLaren [in 1986, pictured at Hockenheim].

"They had to save fuel because everybody was running out at the end of races.

"So nothing has changed there, just that it's become more professional, more accurate, and more detailed."

Rosberg also dismissed suggestions that it means the drivers are not pushing hard during races where fuel saving is critical.

"Even if you are doing it [lifting and coasting], we are still driving at the absolute limit of the car," he said.

"It's just a different kind of driving style, and even that style is very challenging.

"You're still pushing like crazy, you're just driving in a different way."

Fernando Alonso, who hit back on the radio in Canada to a request from McLaren to save fuel, added there are several factors that determine how much fuel a driver has to save.

"There are other things with implications on fuel saving," he said. "The state of charge of the battery at that stage of the race, how much deployment you have [from the MGU-K] on the straights.

"So we have eight or 10 different tasks in a weekend, and there is a variable of 4-5 seconds depending on which session you are driving.

"That's the difficulty, but we are professional drivers."

F1 rookie Carlos Sainz said it is an element of grand prix racing he is not a fan of.

"It's something new for me, I've not been used to it before in my life," said the Spaniard.

"It's not something I really like because I have to do it from early in the race, you are already having to lift and coast.

"You have to adapt and you have to be quick, but probably the amount I was doing in some races was a bit too much in my opinion.

"But it's something I have to do, and something that I have to learn."