McLaren stands ground over shark-fin removal in 2018

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ABU DHABI -- After a back and forth over the pluses and minuses of 'shark fin' engine covers, the controversial aerodynamic devices look set to be banned under next year's technical regulations.

A loop hole in the regulations this year saw the fins return to F1 cars for the first time since 2010, causing debate among fans over the aesthetic appeal of the engine-cover appendage.

After a negative reaction during pre-season testing, the FIA agreed to ban the fins for 2018 but in September the teams had a change of heart and looked set to agree to allow them to remain. The main reason given at the time was that teams could put driver numbers or sponsorship on that part of the car, but in order to overturn the earlier FIA ruling it required unanimous approval from the teams.

McLaren now argues that the shark fin detracts from advertising space on the rear wing and, as a result, will not give its approval for the aero device to remain on cars next year.

"The rear wing is the very valuable spot on the race car and with the current engine fin it blocks the rear wing," McLaren executive director Zak Brown said. "I've only been in the F1 strategy group meetings for a year now, but we don't think enough commercially about some of the technical regulations that we discuss.

"If you look at today's race car, front wings are no longer commercially viable. We've got bargeboards and aerodynamic devices blocking the chassis side and now we've got this big engine fin that blocks the rear wing, so that was really more of a case of starting to free up some commercial locations on the race car."

The fin gives greater rear stability in high-speed corners by helping improve the flow of air to the rear wing. All teams have used some sort of shark fin during the season and they are often combined with a downforce-creating T-wing, which takes advantage of an area of the regulations that allows for a mini wing ahead of the rear wing.

Red Bull team principal Christian Horner said McLaren offered a compromise solution of a smaller shark fin, but it did not perform well in aero simulations.

"A month or so ago we had a meeting and I thought we all agreed that we were going to leave the fin as it was and stick the number there. And then in usual fashion we left the meeting and things changed and Zak decided he couldn't see his rear wing -- he's obviously signed a major sponsor for next year and he's trying to get as much coverage as he can, so McLaren presented another variant.

"The problem is that the aerodynamicists then looked at it and said 'Well, that screws up the rear wing, so we don't want that'. So I'm not quite sure, as we sit here, what we've got.

"I think it goes back to what's in the regulation, which is no fin and so we have to just work out where to stick the number. Maybe we'll have another chat and see if we can persuade Zak this weekend to put the fin back."