Red Bull Team Principal Christian Horner called Formula One's sweeping rule reforms a "fascinating engineering challenge" at the very first pre-season test, already seeming to confess that the 2014 engines might take his team out of its comfort zone.

"This by far is the biggest challenge that we've faced, not so much aerodynamically but mechanically … the shift of emphasis is moving further from chassis to power unit," Horner said at testing in Jerez. Coming from a team with F1's most successful chassis designer and an energy drink company as its owner - as opposed to Mercedes or Ferrari, for instance - these repeated references to mechanical and engineering challenges might already have been a veiled warning from Horner.

As testing then unfolded, the major reliability woes facing the first iteration of the team's RB10 challenger for 2014 became apparent - mainly because the Red Bull rarely left its garage, and when it did, frequently failed to return under its own power.

Over a total of 12 days on the track in Jerez and then Bahrain, Red Bull completed just over 1,700 kilometers (around 1,050 miles). That equates to finishing less than six full F1 race distances in the space of 12 days. It's also barely one-third of the almost 5,000 kilometers completed by Mercedes in exactly the same timeframe this year, and less than a third of the pre-season testing miles covered by last year's Red Bull, the RB9.

"Owing to the few testing laps we completed because of our problems, I can't really say where we stand," Vettel told the Welt am Sonntag newspaper. "Except to say that the others are currently ahead - which is pretty obvious."

The story in terms of pure pace was not much better. Vettel's new teammate Daniel Ricciardo laid down Red Bull's quickest single lap in the most recent two tests at Bahrain. Ricciardo was more than 2.5 seconds adrift of the Bahrain benchmark, set by Felipe Massa in a Williams.

Renault behind the curve early in new engine era

Right now, however, the Red Bull engineers in Milton Keynes and Renault's crew in Viry-Chatillon will surely be most concerned not by lap times, but by an old motor racing adage: to finish first, first you have to finish.

Many of the problems appear to rest with the new Renault "power unit" supplied for Red Bull. After a decade using almost entirely unchanged 2.4-liter V8 engines in F1, teams have jumped to a 1.6-liter V6 engine, plus a turbocharger and two separate elements providing supplementary electrical power.

The four Renault-powered teams regularly languished at the bottom of the testing timesheets and exhibited reliability problems similar to those of Red Bull. Even the three Ferrari-powered teams covered more distance than the Renault engines, despite being outnumbered.

Overheating has been the primary issue for the Renault power trains, with the engine maker confessing that its calculations were skewed by the inaccurate calibration of the dyno it used to test the engine before bolting it into an F1 car.

At the back end of the Red Bull - designed by Adrian Newey, who is famously uncompromising on key features like weight distribution and shape - there is particularly little space for the engine to breathe. Furthermore, any cold air that is directed either underneath or over an F1 car to create downforce and improve handling - Newey's speciality - cannot be sucked through the air intakes to cool the engine.

This might help explain why, of the four teams using a Renault engine, backmarkers Caterham have completed the most laps in testing. It would not be unreasonable to presume the Caterham was the least aerodynamically efficient and most spaciously packaged of the four designs - that the "slower" Caterham is therefore "more kind" to its engine.

Still, rival drivers in the paddock are all understandably wary of writing off the mighty Red Bull before a wheel turns in anger.

"If they can put a few laps together you can see their pace. It looks like it should work from an aerodynamic point of view and, when they get reliability, they will be very competitive," McLaren's Jenson Button cautioned when asked about the Red Bull "crisis."

Slow season, or just a slow start?

Similarly, Vettel was quick to point out that the RB10 racing in Melbourne on March 16 would be drastically different to the package the team took to pre-season testing. But, as Vettel put it, any such process of revision seeking to fix design flaws "would only work immediately and at a stroke in the realm of comic books."

After nine consecutive race wins to round out the 2013 season, it already appears probable that Vettel's streak will end in Melbourne. Yet a slow start to the season would not necessarily ruin his chances. The drastic technical changes Renault and Red Bull are grappling with have affected all teams to some extent, meaning paddock engineers generally expect all the teams to improve their pace at an unusually high rate during the season.

In other words, there's little to no guarantee that the starting grid in Australia this weekend will resemble the one at Abu Dhabi for the season finale on November 23. Yet at this extremely early stage in the race for the 2014 F1 title, the four-time defending champions have plenty of catching up to do.