Vettel's morning benchmark of 1m 22.852s - set on the red-marked supersoft tyres - held over the afternoon. Ferrari therefore finished their pre-season having set the fastest overall time in each of the two tests, and on five of the eight days in total.
Vettel was also the day's busiest runner with 142 laps - a handful more than Carlos Sainz, who remained second for Toro Rosso. The Spaniard was the only driver in the top five to set his best lap on the new ultrasoft tyre.
Williams' Felipe Massa found the biggest gains in the afternoon to jump to third, fractionally ahead of Force India's Sergio Perez - who briefly triggered a red-flag period when he stopped at Turn 11.
Lewis Hamilton also brought proceedings to a halt when his Mercedes hit issues - a transmission problem - for the first time this year in the closing stages of the morning.
The Briton wound up fifth overall, while team mate Nico Rosberg - who took over for the Silver Arrows in the afternoon - propped up the timesheets in 13th.
Red Bull's Daniel Ricciardo, McLaren's Jenson Button and Sauber's Marcus Ericsson all broke the 100-lap barrier, and ended the day in sixth, seventh and ninth respectively.
Renault's Jolyon Palmer edged Ericsson for eighth, while behind Romain Grosjean put Haas 10th, marginally ahead of team mate Esteban Gutierrez - who subbed in for the final hours - and Manor's Rio Haryanto.
The latter managed just one installation lap as the team struggled with technical gremlins in the morning, but had clocked 58 laps when the chequered flag fell to bring the pre-season to a close.
Teams now have two weeks until the season-open in Grand Prix on March 18-20.
Friday's unofficial testing times from Barcelona
|1||Sebastian Vettel||Ferrari SF16-H||1:22.852||142|
|2||Carlos Sainz||Toro Rosso-Ferrari STR11||1:23.134||0.282||133|
|3||Felipe Massa||Williams-Mercedes FW38||1:23.644||0.792||129|
|4||Sergio Perez||Force India-Mercedes VJM09||1:23.721||0.869||60|
|5||Lewis Hamilton||Mercedes F1 W07 Hybrid||1:24.133||1.281||69|
|6||Daniel Ricciardo||Red Bull Racing-TAG Heuer RB12||1:24.427||1.575||123|
|7||Jenson Button||McLaren-Honda MP4-31||1:24.714||1.862||121|
|8||Jolyon Palmer||Renault R.S.16||1:24.859||2.007||90|
|9||Marcus Ericsson||Sauber-Ferrari C35||1:25.031||2.179||132|
|10||Romain Grosjean||Haas-Ferrari VF-16||1:25.255||2.403||66|
|11||Esteban Gutierrez||Haas-Ferrari VF-16||1:25.422||2.570||25|
|12||Rio Haryanto||Manor Racing-Ferrari MRT05||1:25.899||3.047||58|
|13||Nico Rosberg||Mercedes F1 W07 Hybrid||1:26.140||3.288||70|