|Wolff sends further chills down the spines of Mercedes' competitors – not only is Mercedes fast, the engine doesn't fail|
Red Bull only won three races last season, thanks to the efforts of Ricciardo, as their power-unit supplier Renault struggled and Mercedes dominated to win 16 of the 19 Grand Prixs.
Ricciardo and Kvyat, who has replaced Ferrari's new signing Sebastian Vettel in the hot seat, will hit the grid for the first Grand Prix of the season in Melbourne on March 15.
Wolff said they had run the hybrid engine at full power. "You need to run them at 100 per cent because you need to find out when it cracks. This is part of the program – running the engine flat-out – to understand where the problems can be.
"Of course there were problems. You find out about critical issues, you find out where you have more margin – or where you can afford to have less margin – and lots of learning."
Summing up the Silver Arrows' preparations, Wolff said: "It was good. We have achieved some solid mileage, sorted out a lot of problems – it was all about reliability. We worked on the car pretty well with a single engine the entire preseason; that was all we wanted to achieve."