Formula 1 teams head into this week's first pre-season test at Jerez facing a very different set of challenges to recent years.
Teams have become accustomed to very limited running during the winter, as thanks to well-proven frozen engines and, in recent years, relatively stable rules, it has been possible to complete significant mileage straight out of the box.
It will be a different story this year, with the focus during the four-day Jerez test on understanding the new engines.
PERFORMANCE NOT A PRIORITY
Mercedes executive director (technical) Paddy Lowe told AUTOSPORT: "Jerez is focused on powertrain and systems function rather than so much on the chassis performance, aerodynamics, vehicle dynamics and tyres.
"What we want to do in Jerez is understand whether the fundamental package from a powertrain systems point of view is working.
"So we will be doing a mixture of types of runs, short runs and long runs, and systems checks just to exercise the system and make sure that there aren't any fundamental issues."
This week's test at Jerez will be the first time Mercedes, Ferrari and Renault will have run their new engines, which feature new, more powerful energy recovery systems (ERS) that can put out 160bhp.
F1 2014 tech insight: ERS explained
The engines have been years in the making and completed vast dyno mileage, but given their complexity, there will be a lot to learn in Spain.
"It's the first track running of a completely new powertrain," said Mercedes AMG High Performance Powertrains managing director Andy Cowell.
"So the engine, the transmission, the ERS, the cooling systems, a lot of the control electronics to go with it are a lot more sophisticated than what we have become used to.
"So if we are all as reliable as we were in the first test of last year, then it would be a big surprise.
"We are not going there with the intention of having issues, but the reason why you do testing is to shake those issues out before you get to racing."
MORE RED FLAGS EXPECTED
In recent years, new cars have more often than not been able to log significant mileage straight out of the box because the frozen 2.4-litre V8 engines were such a well-proven package.
But with such a large proportion of the 2014 cars all new, including the eight-speed gearboxes that have been designed to deal with the vast torque of the new engines, progress will inevitably be slower this week for everyone.
F1 2014 tech insight: Inside the new turbos
"There will be a lot of red flags next week, I can guarantee that," said Lowe
"We are working as hard as we can and as diligently as we can to make sure that we have less red flags than anyone else.
"We hope to get some good running done over the four days but it will inevitably be slower progress than has been the case in recent years at the first test."
Teams have completed extensive simulation work on the best way to run the new engines, particularly in view of the 100kg per race fuel limit that will place a premium on efficiency.
But once the fundamental reliability of the powertrains is proved, there will be a vast amount to learn about how best to run the engines in the real world.
FROM SIMULATOR TO TRACK
The ERS features two forms of recovered energy: that harvested under braking as with the KERS systems used in 2009 and 2011-13, and also heat energy harvested from the turbo.
Understanding how best to use this energy, which will be controlled from the pitwall rather than by the driver pushing buttons, will be the key to success in races in 2014.
"This is going to be the interesting thing, having the car together in the real world at the race track as opposed to simulation, which is never exactly the same," said Cowell.
"We have put a lot of effort into understanding what technologies we think are best for he best overall efficiency and we have got simulations which we believe are optimum.
"They changed as we got to driver in the loop simulation and undoubtedly it will change and evolve when we go track testing."
Jerez test line-up
|Team||Day 1||Day 2||Day 3||Day 4|
|Red Bull||Sebastian Vettel||Sebastian Vettel||Daniel Ricciardo||Daniel Ricciardo|
|Mercedes||Lewis Hamilton||Nico Rosberg||Lewis Hamilton||Nico Rosberg|
|Ferrari||Kimi Raikkonen||Kimi Raikkonen||Fernando Alonso||Fernando Alonso|
|McLaren||Jenson Button||Jenson Button||Kevin Magnussen||Kevin Magnussen|
|Force India||Sergio Perez||Nico Hulkenberg||Daniel Juncadella||TBC|
|Sauber||Esteban Gutierrez||Esteban Gutierrez||Adrian Sutil||Adrian Sutil|
|Toro Rosso||Jean-Eric Vergne||Daniil Kvyat||Jean-Eric Vergne||Daniil Kvyat|
|Williams||Valtteri Bottas||Valtteri Bottas||Felipe Massa||Felipe Massa|
|Marussia||Max Chilton||Jules Bianchi||Max Chilton||Jules Bianchi|
|Caterham||Marcus Ericsson||Marcus Ericsson||Robin Frijns||Kamui Kobayashi|
Follow the Jerez F1 test as it happens with AUTOSPORT Live from Tuesday morning