Car theft is a global problem but Lewis Hamilton did not expect his McLaren to be pinched by his team-mate, Jenson Button. That, essentially, is what has happened in the buildup to Sunday's European Grand Prix where Button, who has won just two points from a possible 100 in the last four races, has taken the championship leader Hamilton's set-up to use on his own car.

Normally, the pair, who have very different driving styles, have their cars custom-tweaked before each race, but Button's worrying fall from form after winning the opening event in Australia has forced a rethink.

When Hamilton was asked what he thought about Button nicking his set-up here, he said: "It was very interesting. When I went to the factory last week I saw all the top engineers together on one table.

"They had all of my data out, lap by lap, noting all the things I did differently to Jenson to try to understand things. So he has absolutely every detail of what I'm doing differently. So I'm sure we'll see a difference this weekend."

While Hamilton leads the race for the championship, ahead of Fernando Alonso and Sebastian Vettel, Button trails in eighth place, 43 points behind his team-mate. That represents a sharp contrast from last year, when Button became the first McLaren driver to outperform Hamilton over a season.

The set-up for the two cars was roughly similar in the opening race in Australia but they then diverged. According to McLaren's technical director, Paddy Lowe, the team's biggest problem has been to get the front and rear tyres to work in harmony, in terms of temperature and grip. This has proved a bigger problem for Button than Hamilton.

Button is hopeful, though, that he can use Hamilton's success to improve his own fortunes. "It's a very odd championship. I come to every race excited and confident we've improved the car. Canada wasn't a great weekend for me. It was great for the team and Lewis [who won the race]. [But] because it was such a good weekend for Lewis and such a bad one for me it does help in having all that data in understanding why the handling was different and understanding the tyres a lot more.

"Hopefully we've gained a lot of information that will help us both be competitive this weekend. I was baffled but I understand it a lot more now. Trying to understand why we were graining the tyres was a bit more difficult but I think we understand where the damage was being done now after the simulator day. It was a great day.

"I had a different rear suspension [from Lewis] but it wasn't all to do with that. There were little things here and there and it can all build up to make a very different balance, especially with these tyres, where you can definitely fall off a cliff. I did, but Lewis kept it on the edge and did a great job to do so.

"I'm pretty relaxed and confident we've solved it but it's not one issue. It never is. It's many together. I'm confident we've found the problems. It's whether we've done the right things to improve the car."

It is always dangerous to read too much into practice sessions. This was especially true on Friday when anyone who attempted to do so would have received mixed messages.

In the morning session, when McLaren experimented with a new exhaust design – which will not be used on Sunday – Button came through with the fourth best time, four places ahead of Hamilton. But in the afternoon Button was 12th and Hamilton 14th, though the afternoon run was disrupted after the HRT driver Pedro de la Rosa crashed.

The mixed-up results of the two sessions – though Red Bull were strong in both – led to speculation that the eighth race of the season could produce its eighth winner. In that case the favourites would be Romain Grosjean, Michael Schumacher and Sergio Pérez.

The long straights and slow corners of this unremarkable street circuit should suit Schumacher's Mercedes. It is more likely, though, that race day will produce its first double winner of the season. And Vettel, the winner of the past two races here and quickest on Friday afternoon, looks in ominous form.