Red Bull Formula 1 chief Christian Horner has called on the FIA to issue a technical directive to clamp down on teams burning oil as fuel during qualifying, claiming there are “still loopholes” that are being exploited.

The FIA moved last year to tighten the regulations surrounding the forbidden burning of oil as fuel to try and aid consumption and increase horsepower, with tighter restrictions being imposed for the 2018 season.

A technical directive was issued by the FIA last week to enforce parity between the engines used by factory teams and those supplied to its customers, but Horner felt that oil burn was a more important area that needed focusing on.

“I think the other technical directives that have been interesting is obviously the amount of oil consumption and the way that that’s used this year,” Horner said.

“Ideally we’d like to see that go further because it still doesn’t ultimately deal with qualifying. I think it contains the race, but still there are windows of opportunity in qualifying that we’d like to see further closed down.

“It’s mainly between the engine manufacturers and probably worth speaking to Renault about, but we feel there are still loopholes in qualifying that need tidying up regarding consumption.

“We felt that it’s been dealt with in the race, but of course if you were to find a way of using lubricants in a different way in qualifying, it offers a significant performance increase.

“We would like to see belt and braces that closed down.”

In order to curb the burning of oil as fuel, the FIA issued a technical directive ahead of last September’s Italian Grand Prix, reducing the oil consumption of new power unit elements from 1.2 litres per 100 km to 0.9 litres.