Mercedes believes that it has got to the bottom of its poor race performances thus far in 2013 – although that knowledge might not fully translate to the track for a while.
The team has earned two poles in the last two GPs only for the silver cars to quickly slip back come the race.
“We have focused our efforts in two key areas; finalising our upgrade package for Spain and understanding our comparative lack of race pace in Bahrain,” said team principal Ross Brawn.
“We have made progress in the latter area and will evaluate some developments over the upcoming race weekends to help improve the situation. We’re not there yet, but we are making progress and of course, performing in the race is what really counts.”
Meanwhile Toto Wolff added: “We have built a good picture of our varying levels of race performance and why we under-performed overall in Bahrain. In Barcelona, we will test some solutions aimed at improving our tyre management in addition to our planned upgrade package.
“Our target is to improve our Sunday afternoon performance to match what we have delivered on Saturday in the past two races. It will certainly be interesting to see what gains everybody has made since the last time we were at the circuit and how the planned upgrade packages work from car to car.”
Adam Cooper F1 
I wonder how much of this will prove to be true now that Pirelli have backpedalled on the tyre compounds?