Nick Heidfeld insists he is satisfied with his 2011 season despite criticism from within the Renault team.

Nick Heidfeld, Lotus Renault F1 Team
Nick Heidfeld, Lotus Renault F1 Team

Photo by: xpb.cc

Chiefs Gerard Lopez and Eric Boullier have admitted they are disappointed with the performance of the German veteran, who was drafted in to replace the injured Robert Kubica.

Pundit Eddie Jordan speculated to Germany's Sport Bild that the "bullying" tactics could be to spur Heidfeld to quit and make room for Renault hopefuls Bruno Senna or Romain Grosjean.

34-year-old Heidfeld however is vowing to fight on.

"Under the circumstances I am satisfied with the season and with my services," Sport Bild quotes him as saying.

Under the circumstances I am satisfied with the season and with my services

Nick Heidfeld

"I am still fully committed to getting as many points for the team and helping them in whatever way I can," added Heidfeld.

The black R31 will feature updates to the floor, exhaust and suspension at Spa-Francorchamps this weekend.

But technical director James Allison is quoted by France's autohebdo.fr: "At this time of year, the majority of the aerodynamic resources of the teams is transferred to the car for next season."