McLaren stands by its decision to accelerate the introduction of the exhaust-blown diffuser, even though it had to be removed from the cars after problems in Friday practice at Silverstone.
The team had originally intended to introduce the new system for Hockenheim, but brought it forward as other squads successfully added the Red Bull-inspired design to their cars in preceding races. However after a difficult Friday practice in Britain, which saw damage to the McLarens' floors from the hot exhaust gas, the design was taken to revert to the old-style diffuser for the rest of the weekend. While Lewis Hamilton still qualified the revised car in fourth place, his teammate Jenson Button starts back in 14th.
Team boss Martin Whitmarsh said his team had still gathered a lot of information about the system, but acknowledged that its introduction had perhaps been premature.
"I think we have got some ideas, but in truth we need to go away and do our homework," he said. "I think we were trying to bring that forward, it was planned for Germany, we are an ambitious team.
"We want to race, we want to have the most competitive package. We brought it here, probably a little bit earlier than we should have done. I think we learned some interesting things, we learned things about the durability and if you put the rear parts of bodywork in 600 degrees exhaust gas, then you can expect some problems – and we experienced some problems [on Friday].
"We had to make running repairs on the floor during the course of the day, whether that hindered the performance? It certainly didn't help it. And if you looked at the back of the car you could see that it was relatively armour plated at the end of the day, and I suspect that that, in a very critical flow area, doesn't help. But also, the influence of the exhaust – we learned a few things about the shape of the exhaust plume and I think we can optimise the floor around that as well."
He added that the diffuser had proved to be a step forward in some conditions, but also created complications that McLaren had to resolve.
"As the drivers experienced, there was more grip under high throttle conditions and that was a positive of it," Whitmarsh said. "But as you go onto the brakes, your foot is off the throttle, you have closed down that gas supply to the diffuser and the floor in that condition was worse. And it is probably not fun to arrive at some of these high speed corners here without real confidence in the back end of your car."
Whitmarsh reckoned that despite the compromised weekend, the gamble of bringing forward the upgrade had been worthwhile.
"I think we learned a lot. It was a risk. We took it – and I don't regret it," he said. "It put both of our drivers on the back foot. They had to do very quick homework on Saturday morning, aided by Gary Paffett's efforts the night before, but I think they both did a great job."
Despite enduring his worst dry-weather qualifying result since joining McLaren, Button also backed both the decision to try the diffuser, and to remove it again after practice.
"It was the right decision. We had an update package, in some ways it was positive and in other ways it needs some work, we ran with the new front wing and some other parts which are definitely a better fit," he said. "I think the blown diffuser needs a little bit of work as we have found, we understand how it is working, we just have to spend a bit more time before we put it on the car before the race."