to introduce the new engine, and in the interest of saving mileage on the new spec, Honda decided to limit its use to the practice sessions only, using them as test sessions to verify the engines effectiveness and for Alonso to revert to the earlier engine for qualifying and the race, albeit still with the revised MGU-H and turbo. After the Friday practice sessions had concluded, although experiencing a gearbox failure during the test, Honda remained confident and encouraged by the data the new engine showed, feeling it has made a decent step forward with the new unit while also suggesting the aim is for both drivers to have one for the next GP in Austria. Technical partnerships Prior to the start of the season, McLaren secured technical partnerships with BP to provide fuel and Castrol to provide engine lubricants for the RA617H after ending their contract with ExxonMobil who left the fuel and lubricant team sponsorship for Red Bull Racing. The McLaren MCL32 also the first McLaren car to utilize Castrol motor oil and other fluids products since McLaren M30 in 1980. Competition history Pre-season testing As in 2015, McLaren endured a difficult pre-season during testing at the Circuit de Barcelona-Catalunya. The new RA617H, which featured a completely overhauled concept compared to the previous two seasons, was found to be unreliable, interrupting the team's preparations and preventing them from achieving consistent running. Fernando Alonso was particularly critical of the engine, complaining about lack of reliability and power. The team managed to complete only 425 laps in the eight days of testing compared to Mercedes, who completed over one thousand laps in the same period, and had used more engines during pre-season testing than they would be permitted to use during the regular season. The team's initial struggles then prompted reports that McLaren had sought out an alternative engine supplier. Opening rounds McLaren endured a difficult start to the season. Alonso retired from 10th with bodywork damage at the Australian Grand Prix, while Vandoorne finished 13th, despite having dashboard damage. Alonso had a good start at the next race in China, jumping up to 6th, before retiring with a driveshaft failure. Vandoorne retired with fuel system issues. Bahrain was a bad race for the team as Vandoorne couldn't start the race due to water pressure issues and Alonso retired late in the race with power unit issues. Alonso couldn't start