Red Bull Racing has dismissed talk that its new exhaust configuration is pushing the limits of Formula 1's technical regulations, despite suggestions from rival teams that the FIA may need to look at it.
The reigning world champions revealed its latest aerodynamic package on the penultimate day of last week's Barcelona test - with the exhausts situated as far forward as possible so as to help energise airflow around the Coke-bottle area of the car.
The fact that there appear to be slots in the rear floor area of the RB8 has led rivals to suspect that Red Bull Racing could even be trying to direct exhaust flow into the diffuser area - something that the new regulations was supposed to have outlawed.
Some of Red Bull Racing's rivals have expressed interest in what Red Bull Racing is up to - and think the FIA's head of technical department Charlie Whiting should take a close look at the design.
But Red Bull Racing team principal Christian Horner says his team sees no issue with its design - which is similar to the concept also being used by Sauber and McLaren.
"We are happy that we comply with the regulations," Horner told AUTOSPORT. "Ultimately it is a matter for the scrutineers and the FIA, as they have more knowledge and sight. Teams only ever get to see photographs; the FIA gets to see the cars close up in reality."
Ferrari technical chief Pat Fry believes that teams may need further guidance on what they are and are not allowed to do in light of the Red Bull Racing design.
"It comes down to what re-ingested exhaust gas is really and that's a question for Charlie," said Fry, referring to a technical directive issued by Whiting earlier this year.
In that note to the teams, Whiting made it clear any exhaust designs that re-ingested or redirected exhaust flow for principally aerodynamic reasons would not be permitted.
Ferrari had to abandon an exhaust concept similar to Red Bull's prior to last week's Barcelona test, and Fry says its development push in this area would now depend on what Whiting allowed teams to do.
"I think it's the obvious direction to go in," he said about the Red Bull design. "We gave it a shot; we didn't quite get it right. The issues we had, we weren't going to solve for at least the first four races, so that's why we had to back up and change course.
"Ultimately I think it is the way to get the most downforce out of the current rules, obviously depending on Charlie's interpretation, so we are continuing to look in that area, as I'm sure is the whole pit lane."
Williams chief operations engineer Mark Gillan said in Barcelona that the Red Bull design was worth looking at, but he felt questions on whether it complied with the spirit of the regulations would be left to the FIA.
"With all these things, it is not for me to question the legality of a team," he explained. "That is down to the team and the FIA. I look at our car and obviously we watch what others are doing very carefully and if we deem there is performance to be had there, we will be looking at it ourselves. They have got an interesting solution and we have certainly looked at it."
"Obviously all teams go to the limit of where they perceive the regulations to be, provided they are getting performance benefit from it."
When asked whether he believed it complied with Whiting's technical directive, Gillan said: "It is re-ingestion of exhaust gases into the bodywork. When it goes external it is a bit more vague."
* This week's AUTOSPORT reveals detailed technical drawings of the new Red Bull Racing exhausts and slots in the rear wing that appeared in the final Barcelona test