The handling of the new generation of Formula One cars is more susceptible to wind conditions, according to Mercedes driver Valtteri Bottas.
Last week's test at the Circuit de Catalunya was the first time the new cars took to the track with race specification tyres fitted. By the third day of testing Bottas' Mercedes had reached F1's stated target of being five seconds per lap quicker than the 2015 cars, with the majority of performance coming from the reworked aerodynamic packages.
"In terms of performance, lap time wise, I think the main proportion of the gains come from the aero, but it is very difficult to calculate exactly how much comes from the tyres," Bottas said.