Formula 1 teams need to do more to help improve overtaking in the sport, claims BMW motorsport director Mario Theissen.
With the first half of this season having delivered mixed results from an overhaul of the aerodynamic regulations, Theissen believes that work on boosting the spectacle has not been as successful as those aimed at reducing costs.
"In the area of cost-saving, I think the progress has pretty much met expectations," Theissen told the official BMW Sauber website.
"The aero restrictions we currently have, however, are not as tight as we thought they would be, so I think we could do more."
He added: "When it comes to overtaking maybe we had expected a bit more from the new regulations."
Theissen believes that the rules have had one positive consequence, however, in closing the field up.
"It has been very exciting for both the spectators and us, sometimes too exciting," he said. "You see almost every team going out on two sets of fresh option tyres, even in the first knockout phase of qualifying, in order to make it into the second phase.
"That is a scenario no-one expected and we haven't seen in the past 10 years."