I don't think any of the top field cars will have their engines 'turned up' as they need them to last... they can draw conclusions on performance even at lower engine modes as it generally only affects acceleration and they can accurately predict that. what will make a difference though is how the cars are using their tyres which the RB has been amazing at and the Ferrari where good at for one lap. It would be good for Mercedes to be competitive though as that will mean Perez has to push hard and that will be fun to watch!


