McLaren has decided to revert back to standard specification for the rest of the British GP weekend after struggling with the update package on Friday.
The team experienced some problems with getting the car to work in its new configuration, especially after a set-up change between sessions made the car particularly difficult over the bumps. There were also some issues with cooling that had to be addressed. In the second session Lewis Hamilton was eighth and Jenson Button only 13th.
The reversal is not as big a deal as it might first sound because the cars were scheduled for engine and gearbox changes anyway on Friday evening, so in effect the team is just rebuilding them with different bodywork, floor, exhausts and heat shielding.
If nothing else the team now has some useful knowledge with which to try again at Hockenheim with the new spec.
Adam Cooper F1 
Smart move!
One of the results of the ban on in season testing is that teams have to resort to such “last minute” testing as we saw this week end.
Better to play it safe and see what they can come up with for the next race when they have had more time with simulations, etc.
McLaren need to do one of those “media days” like Ferrari did a few weeks back to sort it 🙂