Ferrari may have topped the times at Barcelona in Spain last week, but the Formula 1 team heads into the final test aware it needs answers on both its reliability and performance.
For while the headline times set by Sebastian Vettel and Kimi Raikkonen may have appeared on the surface to be a statement of intent, the team has not seen anything yet that indicates it has made a massive jump past Mercedes.
Testing times often only give a hint of ultimate potential, and rarely do the end of day time sheets give the true story of exactly what has been going on.
In simple terms, the performance of the various tyre compounds already meant that simple calculations put Vettel's best overall lap on ultrasofts behind that of Nico Hulkenberg (supersoft) and Nico Rosberg (mediums).
But while Hulkenberg was unlikely to have been running with a heavy fuel load, judging by the Mercedes programme, you can be sure that the Silver Arrows was not showboating.
In fact, with F1 performance coming down to the final tenths, there is already talk that the best laps of the test will be much quicker this week, with one insider suggesting they could get down to the 1m19s levels.
Only then will we see just how the Ferrari really stacks up against Mercedes.
While no one has answers on performance yet ahead of a second test, where teams will likely push for times, it is on the mileage stakes that Ferrari cannot be yet satisfied.
The Maranello outfit completed just 272 laps over the four days of running at Barcelona last week, well short of the 490 laps delivered by Mercedes.
It was also less than the Sauber and Toro Rosso teams, who were running Ferrari's 2015 specification power unit.
And while Mercedes was pounding around lap after lap – forcing the team to limit the mileage of its drivers so they did not get exhausted – it did not go unnoticed that Kimi Raikkonen found himself stuck in the garage at times with what were understood to be fuel pump and MGU-K issues.
Indeed, sources have suggested that the team is not yet fully satisfied with the reliability of its newly repackaged MGU-K, which is why it was not able to push it to the limit over longer distances just yet.
It was interesting to note that Ferrari was the only team not making any of its technical staff available to speak to the media – which can often be a sign that a team has something to hide.
Improvements will certainly come, and that it why it will be both the ultimate lap time, and the distance covered, which will show us just how on track Ferrari is with its preparations this week.
Additional reporting by Franco Nugnes