Highlights - German GP qualifying
By Sarah Holt
BBC Sport in Hockenheim
Michael Schumacher has called the ban on in-season testing "ridiculous" after Mercedes struggled in qualifying for the German Grand Prix.
Schumacher qualified 11th, two places behind team-mate Nico Rosberg after failing to get to grips with the effect of running with a modified diffuser.
"It is completely ridiculous to do zero [testing]," said Schumacher.
"Some kind of testing should be implemented. I hope there is common sense and we find a solution."
Mercedes had arrived at their home race in Hockenheim with a modification to their exhaust blown diffuser and a new rear wing.
Mercedes didn't meet expectation - Schumacher
However, Schumacher, Rosberg and team principal Ross Brawn admitted they could not make the latest upgrades work, especially as the wet running on Friday hampered evaluation.
Both drivers blamed inconsistencies with their cars for the disappointing qualifying display at their home race, but Schumacher made it clear he believes the testing ban is severely restricting the team's chances of catching Red Bull, McLaren and Ferrari in the development race.
"Certainly we are disappointed," stated Schumacher. "Our expectation was to be about fifth or sixth.
"We were not close enough to this and there are reasons.
"If you don't have aerodynamic features - like the F-duct or the exhaust blown diffuser - then you want to implement them, so you develop them at home, build them on to the car and test them on the race weekend," explained Schumacher, who was used to unlimited testing in his previous Formula 1 career.
"Naturally, you have very little time and you end up in some compromises.
"It's a tough way to fight your way through the development, but as a consequence here and there you have some issues.
"I understand why we have ended up where we are right now, but as it was ridiculous to do 90,000 kilometres more during the year of testing it is completely ridiculous to do zero."
Rosberg squeezed into the final qualifying session in 10th but could barely improve with ninth place.
"The car was definitely inconsistent throughout the weekend," said the 25-year-old German, who had appeared to make a step forward after taking third last time out in Silverstone.
"Going into qualifying my balance and my grip level on the rear changed a lot. I had a lot of oversteer and I couldn't do much about it.
Mercedes performance flummoxes Brawn
"It took me by surprise a little bit - I didn't see it coming after free practice."
With a two-week shutdown looming in August, when teams are banned from working on the development of their cars, Brawn wants to use every opportunity to find out why the team are struggling to find extra performance from their updates.
"We have quite a lot of new parts on the cars this weekend and it looks like there may be something there with the floor," said Brawn.
"We will be working hard between now and [next weekend's race in] Hungary to understand the system and to make improvements.
"We are seeing some differences in the behaviour of the car and that is aggravating the understanding of the tyres.
"There have been little windows this weekend when the car has looked OK but when it came to qualifying a number of cars moved away from us quite strongly."