Honda will bring a hugely upgraded power unit to the Japanese Grand Prix which could elevate Toro Rosso into contention for 'best of the rest' honours. According to Sky Sports, Honda's upgrade will be worth a monumental half a second per lap, news which will also prick the ears of Red Bull.
Pierre Gasly and Brendon Hartley trialled the new parts in Friday practice in Russia, before reverting to their previous-spec engines over the weekend.
Any power boost would have been wasted in Sochi as both Toro Rosso drivers retired inside six laps due to brake failure.
However, with a trip to Honda heartland Suzuka coming this week, Red Bull's junior team could be a real factor in the midfield battle.
Although Hartley and Gasly only took part in Q1 in Sochi, the Frenchman would have been seventh-fastest in the session if half a second was shaved from his time.
"There is a bright shining light on the horizon in the back of this Toro Rosso, which is the Honda engine," Skyreporter Ted Kravitz said in his Sochi 'Notebook'.
"[Toro Rosso] did Friday with the new Honda engine, then they had to take it out because they need some more calibration on it and they want to keep it fresh for Suzuka of course – Honda's home race.
"Apparently it's brilliant. Apparently this new Honda engine is the 'jewel' that Ron Dennis talked about years a go.
"This new Honda engine is worth half a second per lap more than the engine they’ve got in at the moment.
"Looks good for Red Bull Racing next year if they can get it reliable, that's the big question mark."