 With each engine manufacturer on the 2015 grid being granted some limited scope to develop their engines , McLaren and Honda were given some leeway to develop the RA615H power unit before it was required to be homologated despite having had eighteen months of uninterrupted development prior to the first race . Under the 2015 regulations , the power units were divided into thirty @-@ two areas for development , and Honda were given permission to develop nine over the course of the season . The first engine updates were introduced at the Canadian Grand Prix , aimed at improving the reliability of the motor generator units , but by mid @-@ season , the engine was reported to be producing 120 bhp ( 89 kW ) less power than the Mercedes <unk> Hybrid engine , the benchmark of the 2015 grid . 
