Assessing the hybrid revolution - the mid-term tech report

For the 2014 season, Formula One racing undertook the most comprehensive regulation changes seen in the last three decades, with a move to more fuel efficient, hybrid turbocharged power units.

With 11 of the year's 19 Grands Prix complete, F1 technical expert Gary Anderson looks back on how these changes have played out so far - and looks ahead to what we can expect in the remaining races