They've been chewing through tyres all year, they've just not had to push as hard as in the past 5-6 races where their tyre wear has appeared to get worse, simply because the Mclaren is so improved in the past 5-6 races and Ferrari aswell.
I do wonder if they are doing slow but fast enough q1, same tyres, fast enough in q2, then do a faster lap in q3, on hards, do a longer first stint on hard tyres.
I really don't know, if they do one supersoft stint in the race and the rest all on harder tyres.
Hamilton on an awesome lap but this is the thing, Hamilton/Button didn't need to go that fast in q1, nor this fast in q2.
Too often recently Hamilton has done a good enough lap in Q2, panicked and done a softer tyre lap in Q2 when he hasn't needed to.
Maybe RBR have, miles after they and everyone else should have, realised that fast enough is better than super fast in q1/q2.