Christian Horner says F1 could undergo a dramatic change to the pecking order next season when the new engine regulations come into effect.
Next season Formula One bids farewell to the current 2.4 litre V8 engines and welcomes in a new era of 1.6 litre turbocharged V6s.
With the new engines comes a new set of challenges as the same races on this year's calendar will need to be covered using 50kgs less fuel than at present while still getting a power output of 750hp.
Red Bull will be sticking with Renault power through the change with Horner admitting F1's pecking order could be altered if an engine supplier or team misses the mark.
"I think that for sure 2014 is going to be a risk for everyone," the Red Bull team boss told Autosport.
"Nobody knows where anybody is with their respective engines at the moment, and you can see within Viry [Renault's engine headquarters] there is a lot of determination and a lot of good work going on.
"Renault has a tremendous track record and we have a lot of faith in the engineers at Viry. You can see where they are with their programme, while Mercedes and Ferrari are also pushing extremely hard as well.
"The racing in F1 next year could be quite different, and there could be more focus on economy than absolute performance. It will be an interesting challenge.
"We have confidence in our engine partner, but we will only know in 2014."
The Brit also rubbished suggestions that Ferrari and Mercedes could have the upper hand next season as they produce both the engine and the chassis.
"I think we have an extremely good relationship with the guys in Viry. And we have a clear [works] status with Renault," Horner added.
"There has been an awful lot of exchange of design ideas, and the way you integrate your chassis and your power plant into your chassis is a clear element.
"Whether it is Mercedes in Brackley dealing with Brixworth or Milton Keynes dealing with Viry, that relationship I would assume is reasonably similar."
