Hot on the heels of Felipe Massa's exclusion from the Brazilian Grand Prix due to tyre temperature irregularities, World Champion Lewis Hamilton claims his all-conquering Mercedes machine just isn't the same since changes to tyre pressures came into effect for the Singapore Grand. Since both the cars of Hamilton and Rosberg judged to be running incorrect tyre pressures ahead of the Grand Prix in Monza (though it escaped punishment as Mercedes had broken no rules or procedures) changes made for Singapore onwards seem to have affected the results achieved by the British driver far more than his German colleague Nico Rosberg. Despite no firm evidence that the necessary changes made to the tyre pressures have caused Hamilton's recent (relative) dip in form, the World Champion does suggest his car hasn't performed quite like it did in the early part of the season. "From Singapore onwards there's been a change to the car – but whether or not that's made a difference, I don't know really. We'll have to see. But it has changed since Singapore". Without a pole position since September's race in Monza, and with Rosberg's recent run of five pole positions and back-to-back race wins in Brazil and Mexico (not to mention leading in Austin until suffering an unforced error to let Hamilton past) the question was posed over whether changes to the tyre pressures could have had an effect. Rosberg refuted these allegations however, claiming the change in the status quo at the head of the field is simply down to the number 6 Mercedes upping its game in recent races. Questioned by Sky Sports F1 after Sunday's race regarding Rosberg's upturn in form potentially being due to the release of the pressure of fighting for a championship title, Rosberg simply replied that his form has improved and the pressure remains as before. With Hamilton having won three Grands Prix since the Italian Grand Prix, this is hardly a disaster for the Briton, it does however hold out a little ray of hope in the F1 paddock that maybe next season he won't have the championship race all to himself.