|Kimi Raikkonen's Ferrari appears to be quick|
Ferrari's Kimi Raikkonen led morning practice in Barcelona, lapping the Circuit de Catalunya with a time of 1.18.634s. Red Bull's Max Verstappen was second 8-tenths behind the Finn, with Toro Rosso's Carlos Sainz third 1.2s behind Raikkonen.
McLaren-Honda's dismal pre-season testing programme continued amid more electrical problems.
McLaren has been beset by a lack of reliability and performance across testing in Spain, with a shortage of laps and pace characterising its build-up to the 2017 campaign.
Stoffel Vandoorne amassed only 48 laps on Thursday, stopping twice on track due to an electrical issue, a day after Fernando Alonso openly criticised power unit supplier Honda.
Alonso returned to the MCL32 for the final day of testing on Friday but came to a halt at Turn 9 just over two hours into the session, causing the red flags to be deployed.
Alonso reappeared 35 minutes later but crawled to a stop once more, ending his running after just 17 full laps, his quickest time, set on Ultra Softs, over four seconds behind leader Kimi RÃ¤ikkÃ¶nen.
"Fernando has stopped out on track with the same issue that Stoffel encountered yesterday – intermittent electrical shutdown," a McLaren spokesperson confirmed.
"Various electrical components in the PU and chassis were changed overnight.
"The team are making further changes to eliminate variables and identify the source of the problem."
McLaren, along with its rivals, has just four hours of running remaining on Friday afternoon before the first practice session in Australia on March 24.
Brian Carroccio reporting for AutoRacing1
1. Kimi Raikkonen – 1.18.634 (Super Soft), 48 laps
2. Max Verstappen – 1.19.438 (Super Soft), 33 laps
3. Carlos Sainz Jr. – 1.19.837 (Ultra Soft), 39 laps
4. Valtteri Bottas – 1.19.845 (Super Soft), 52 laps
5. Nico Hulkenberg – 1.19.885 (Ultra Soft), 45 laps
6. Sergio Perez – 1.20.116 (Ultra Soft), 46 laps
7. Lance Stroll – 1.20.335 (Soft), 59 laps
8. Romain Grosjean – 1.21.429 (Soft), 43 laps
9. Marcus Ericsson – 1.21.670 (Ultra Soft), 59 laps
10. Fernando Alonso – 1.22.731 (Ultra Soft), 19 laps