Winter Testing Barcelona – Day 4: Hamilton in Charge, Reliability in the Spotlight
Fourth day of private testing on the famous Spanish track and finally the teams have been able to make up for lost mileage. As times evolved during the session, Lewis Hamilton asserted his dominance on the clock ahead of Stoffel Vandoorne's McLaren and Sebastian Vettel's Ferrari.

After Wednesday’s improbable snowy day, the teams were eager to make up for lost time in the winter testing.
It is under a sky heavy with humidity and with cool temperatures that the day of running begins at the Catalonia circuit. The first hours were completed by the single-seaters on rain tires.
The weather conditions then improved with dry weather and a temperature rising to around 13-15°C. As a result, the lunch break was canceled.
The favorable conditions allowed the cars to be equipped with slick tires, drastically improving lap times.
From over 2 minutes per lap on wet tires, the best times of the day went under one minute twenty.
But beyond pure performance, reliability takes the spotlight with more than 1,101 laps completed by the fifteen single-seaters that ran today.
Pierre Gasly’s Torro Rosso completed 147 test laps. A true feat for engine supplier Honda when we recall the previous winter tests, which were disastrous for the Japanese firm.
Sebastian Vettel’s Ferrari and Stoffel Vandoorne’s McLaren also took full advantage of the good track conditions, completing 120 and 110 laps respectively.
We certainly made up for the lost running yesterday, 147 laps! 💪
Time to put your feet up, Pierre! pic.twitter.com/rpRnwrsOBX
— Toro Rosso (@ToroRosso) 1 mars 2018
Thus, the different engines have fully delivered satisfaction in terms of reliability with 245 laps for Renault, 248 for Mercedes, 354 for Ferrari, and 147 for Honda, all completed by Pierre Gasly.
Only two off-track incidents are to report. Max Verstappen indeed finished turn 12 of the circuit in the gravel, explaining his low mileage of 35 laps.
Marcus Ericsson also lost control of his car during this test day.
We’re back to green after this brief trip to the gravel for Verstappen#F1 #F1Testing pic.twitter.com/3W1sLLmgxk
— Formula 1 (@F1) 1 mars 2018
In view of the times achieved, it’s an imperial Lewis Hamilton who sets the fastest lap with a time of 1:19:333 on medium tires!
Stoffel Vandoorne and his Renault-powered McLaren follow closely by half a second with his time of 1:19:854. The Belgian, on the other hand, was equipped with hyper-soft tires.
The trio of the best times is completed by Sebastian Vettel with 1:20.241 on soft tires.
This fourth day has therefore been most beneficial to the teams, allowing 13 drivers to complete more than 90 laps, following the previous days that were complicated due to weather conditions.
Beyond the importance of these test days, the reliability of the engines, which left something to be desired for some manufacturers, seems to have improved.
A case to follow starting Tuesday, for the first day of the second and final week of winter testing.
Times and lap counts from a very productive Thursday at @Circuitcat_eng
Almost the entire field got a feel for the conditions 💪#F1 #F1Testing pic.twitter.com/BFUSkd0j2Z
— Formula 1 (@F1) 1 mars 2018