The setup changes, according to the official FIA release (the FIA are always fully aware of setup/parts changes because they always have a spec sheet, and a setup sheet for every competitive session) were: new gearbox, change of gear ratios, and change of suspension setup. Other areas (such as aero) were unchanged.
As such, Vettel would basically have had WORSE DRS-closed top speed, but had BETTER DRS-open top speed. Obviously we don’t know what changes were made to the setup, so we cannot really judge what impact those would have had.
As such, over a lap, Vettel’s clean air laptime would have been hurt, but he would have a better chance of overtaking on the straights due to having a better top speed.
As for the car being set-up for top speed, did you see Vettel have to overdrive his car to keep up with the other cars?
No. Probably the reason he could keep up.
Personally, I never saw the Red Bull twitch at all like the Ferrari and it was keeping up with the other cars.
Yep – that would’ve been the REASON why it would have kept up better.
Like I’ve said over and over again – ask anyone in motorsport. If a car is being driven over a lap twitchy, it’s slow. Even if it’s an HRT, or a Ferrari F2012 – a twitchy lap = slow. This is not to say a tidy lap = quick, but driving a car 99% is WAY quicker than driving a car 101%.