Mat Coch writes:

As teams hastily develop their own version of McLaren's F-duct, Martin Whitmarsh and Christian Horner are at odds over the spirit of the rules surrounding the system's legality, as well as its performance bonus.

"It's probably been a little bit overstated," Whitmarsh told Pitpass this morning. The system, he claims, is only worth a tenth of a second around the Albert Park circuit, though he admitted that gains would vary from circuit to circuit. "In Formula One terms, a tenth is the difference between pole and not being on pole," he added.

Rival team boss Christian Horner disagrees. "I think it's worth a little more than a tenth of a second," he argued.

Horner was also critical of the system and its impact on development costs to teams. The sport has been actively tying to reduce costs, and Horner feels developments such as the F-duct undermine those efforts.

Whitmarsh however, believes the system is perfectly reasonable, claiming that development in every area is part of the Formula One ethos. "Every part of the car you try and do what you can to find the best possible performance," he said.

Back to Horner, who refutes Whitmarsh's claim. "You've got to look at the spirit of the regulations sometimes with these things, and that clearly is against the spirit but not against the letter of the law."

Red Bull is now developing its own version of the system, Horner admitted, confirming comments made by Adrian Newey to Pitpass. "Unfortunately with that system now legal the teams will be pursuing their own versions. If you include all the man hours that will go into it, it's certainly not cheap."