Sebastian Vettel tops the midday timesheets at the Circuit de Catalunya.

Between them, the eleven drivers on duty completed 328 laps this morning, as F1 returned with a vengeance.

Following a flurry of launches and the consequent photo-opportunities, it was Lewis Hamilton who kicked things off, the world champion heading out on to the Barcelona track dead on the stroke of 9.

Following overnight rain the track remained damp for the first couple of hours until the sun finally broke through.

Due to the conditions, Inters were the order of the day initially, but as they improved drivers switched to Pirelli's medium compound rubber.

Whilst Vettel is setting the pace, Mercedes is once again showing awesome reliability, Hamilton completing almost double the mileage of any other driver.

Third quickest was early pace-setter Valtteri Bottas, the Williams driver completing 43 laps, making him the second busiest driver.

It's engine supply issue on the back burner for now, the Tag-Heuer powered Red Bull, in the hands of Daniel Ricciardo, completed 20laps on the way to posting the fourth best time of the morning.

It was a promising start for McLaren also, Jenson Button completing 35 laps this morning, just under the amount it completed in the first three days of last year's opening test at Jerez.

Only one red flag thus far, and that dubious honour goes to the new kids on the block, Romain Grosjean suffering a high-speed front wing failure that left debris on the pit straight and necessitated the deployment of the marshals and their brooms.

Far too early to be reading anything into the times other than the fact that the Mercedes has its reliability, Ferrari has the pace and Manor has opted for a decent (i.e. non-grey) livery.

Morning Times - All Times Unofficial

Name	Team	Laps	Time	Gap
Vettel	Ferrari	36	1:24.939	122.594 mph
Hamilton	Mercedes	66	1:25.409	0.470
Bottas	Williams	43	1:26.091	1.152
Ricciardo	Red Bull	20	1:26.704	1.765
Sainz	Toro Rosso	35	1:27.180	2.241
Button	McLaren	35	1:27.691	2.752
Ericsson	Sauber	36	1:28.165	3.226
Grosjean	Haas	13	1:28.399	3.460
Celis	Force India	21	1:29.406	4.467
Palmer	Renault	15	1:31.351	6.412
Wehrlein	Manor	8	1:33.455	8.516