McLaren executive director Zak Brown has defended the team’s decision to block a rule change that would have seen ‘shark fins’ stay in Formula 1 next season.

The elongated engine covers were a byproduct of the new aerodynamic regulations this season and led to largely negative feedback from fans during pre-season testing. The FIA moved to ban the fin – many of which also carry small wings for added downforce on the end – from 2018, but teams then agreed to stick with the current solutions in order to allow driver numbers and sponsors to be displayed.

However, that agreement means the regulations have to be changed again after the FIA’s move to ban the shark fin, a move that would require the unanimous approval of all teams due to the proximity to the new season. At the latest meeting, McLaren blocked such a change, with Brown explaining the thinking is from a commercial rather than performance point of view.

“The rear wing is the very valuable spot on the racecar and with the current engine fin, it blocks the rear wing,” 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 racecar, 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 racecar.”

Red Bull team principal Christian Horner says McLaren did present another proposal for the engine cover that was rejected by the other teams.

“A month or so ago we had a meeting and I though we all agreed that we were going to leave the fin as it was and stick the number there,” Horner said. “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 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.”

And Ferrari boss Maurizio Arrivabene hinted he believes McLaren wants to make the change for an aerodynamic benefit as the fin’s removal would lead to less sponsorship room overall.

“I’m quite neutral; I’m waiting for a decision,” Arrivabene said. “What is quite funny is that Zak said that the fin was interfering with the rear wing, and in the meantime he said he would like to have more commercial space. So somehow he is removing the fin and doesn’t have anymore that commercial space, and on top he needs to find space for the number, so I think there is something wrong here.”