Toro Rosso's technical director James Key says the Renault engine used in his team's car has made a big step in terms of performance this year.
Although Toro Rosso got off to a slow start during the first week of testing with reliability problems and a best lap time that was over three seconds off the pace set by Mercedes, the team is still targeting a strong position in the midfield this season. After using a year-old Ferrari power unit last year, the switch to Renault power should help the team move up the grid and Key said he has been impressed by the figures he has seen from the engine so far.