Toro Rosso falls behind Red Bull development

Toro Rosso is expecting to spend at least one more Grand Prix at the very tail end of the Formula One grid.

While the similar car of the parent team Red Bull Racing utterly dominated the British GP, Sebastiens Buemi and Bourdais struggled at Silverstone to fend off the Force India challenge.

"We have a different engine, different cooling and different suspension to Red Bull," the Swiss rookie Buemi told Germany's Auto Motor und Sport.

The real problem, however, is that the STR4 has now fallen far behind the development specification of the Red Bull RB5.

For example, while the Toro Rosso will debut its first double diffuser in Hungary late next month - Red Bull's Monaco version - Red Bull finished one-two at Silverstone with a subsequent development of the rear aerodynamic concept.

The two Red Bull Technology cars also now look visibly different, after RBR fitted a significantly wider front nose to the RB5 driven by Mark Webber and Sebastian Vettel in Britain.

Team boss Franz Tost admits the development discrepancy is a problem for Toro Rosso.

"We suffer from the lack of new specification aero parts," he said. "We will have these for Hungary, when I expect and hope that this will bring us back to the front end of the midfield."

Bourdais commented: "We have what we have and need to make the best of it until the new diffuser comes."