Although motor racing's governing body has begun a clampdown on the activity, with teams restricted on the amount that can be burned, there remain big concerns that the area is still being heavily exploited.

Furthermore, questions have started being raised about whether F1 can boast environmentally-friendly engine technology if cars are burning more than two litres of oil in a race.

Although a 0.6-litre per 100km limit is set to be rigorously enforced from next year, McLaren racing director Eric Boullier thinks the FIA needs to get even tougher – and perhaps outlaw the activity completely.

"This situation is a little bit difficult to understand," explained Boullier. "Oil burning is used for performance, there is no secret in that, but a normal engine working with any road cars or racing for us, there is no oil burning.

"There is something which the FIA is trying to stop, because oil burning, it's not very friendly for the environment. And obviously if there is a performance [boost] they need to close it down. Next year we'll see.

"I know the FIA and Charlie [Whiting] are working very hard to try to close the loophole because there's not a clear definition of oil in the FIA regulations, but I don't know if it's going to be enough.

"We have to also clamp [down on] this oil consumption, which would be at the end closing the loophole for next year. I think the restriction may [need to] be a bit higher than it is planned to be today."

Rigorous enforcement

Mercedes motorsport boss Toto Wolff believes that the key thing was for the FIA to rigorously enforce the limits it has imposed, as he admitted that teams had to chase any competitive advantage they could.

"It is one discussion to have an environmentally friendly discussion, but on the other side it is important to comply to the rules," he said.

"It has been made clear by the FIA after Baku that there shouldn't be any oil burning, or if there was, the oil consumption was limited to 0.9 litres [for the remainder of 2017]. There wouldn't be any loopholes to circumvent that.

"I think the FIA needs to be robust in just following up what they have expressed as being legal and not legal."

When asked if he felt next year's oil burn restrictions went far enough, he said: "I think whatever the level is, it just needs to be policed in the right way so it is the same playing field for everybody."

Honda's F1 engine chief Yusuke Hasegawa said that all manufacturers were aware of the competitive benefits of oil burning.

"Of course the FIA try to modify the regulations, to restrict any oil burn for next year, but in this competition everybody is finding out something extra," he said.