What a difference a day makes.

Red Bull were left ruing their misfortune after day one in Bahrain, having only completed a pitiful 24 laps in five days since Jerez testing in January, yet bounced back to get a solid run out on day two.

Four time world drivers' champion Sebastian Vettel completed 59 laps on the second day, which is a huge improvement for the team, who had been blighted by Renault's engine problems and by concerns over the new RB-10's bodywork.

The German was ecstatic about his chance to get to grips with his new machine.

He said: "We did more laps today than so far the whole year, which is a huge step forward.

"We are learning every lap so we are trying to run as much as possible even if the quality of the lap is not the best, but the most important thing for us at this stage is simply to run."

Whilst Red Bull are just getting their feet on the ladder of 2014, it is McLaren and Mercedes who appear to have made the biggest strides forward in pre-season, having both backed the seemingly more reliable Mercedes power units.

McLaren's new driver Kevin Magnussen went quickest of all in today's test, 1.535 seconds clear of Force India's Nico Hulkenburg, with Fernando Alonso 1.606s behind the Dane and the Spaniard's Ferrari 0.449s ahead of Nico Rosberg, of Mercedes.

And whilst timings are fairly irrelevant at this stage, novice Magnussen will have gained some valuable experience on this year's McLaren model, which will aid him in the feel of it for the season ahead.

Mercedes - who have had the most reliable engine so far, as well as arguably the most fruitful pre-season - had to stop a race-simulation run for Rosberg following sensor failures, in the first major teething problems the team have experienced.

Williams also got some worthwhile data on-board, with Valtteri Bottas completing the most laps of the day, a hefty 115 of them, with Alonso and Rosberg each mustering 96 and 84 respectively.

Conversely, Marussia struggled on day two, with Max Chilton only able to post 17 laps, and Lotus' number one Romain Grosjean only able to complete 18.

Overall lap totals by each engine manufacturer during pre-season:
Mercedes - 1416
Ferrari - 761
Renault - 445.

Overall lap totals by each team during pre-season:
Mercedes - 467.
Ferrari - 411.
McLaren - 371.
Sauber - 300.
Williams - 295.
Force India - 283.
Caterham - 209
Toro Rosso - 117
Red Bull - 93.
Marussia - 50.
Lotus - 26.