By Alan Baldwin
LONDON, Feb 20 (Reuters) - Red Bull are hoping Renault 's revamped engine will give them the power to take on champions Mercedes in a new-look Formula One this season.
"It's a brand new engine this year, a change of philosophy," team principal Christian Horner said in a pre-season interview conducted by the team. "They ( Renault (PA:RENA)) have had a big winter.
"We're hoping for a step up in performance and if that's delivered then hopefully we can really be a challenger team this year and give the Mercedes and Ferraris a hard time."
Red Bull's Renault engines, branded as Tag-Heuer, powered the team to two wins last season with Dutch teenager Max Verstappen and Australian Daniel Ricciardo.
They were the only drivers apart from Mercedes' Lewis Hamilton and now-retired world champion Nico Rosberg to win races in 2016.
The rules have been rewritten this year, with cars expected to lap significantly faster on wider tyres.
As with any change to the status quo, Horner saw a development battle stretching out from the start of the season in Australia on March 26 all the way to Abu Dhabi on Nov. 26.
"What excites us most about 2017 is the opportunities that arise from these new regulations. It's going to be fascinating to see who's got it right and who's got it wrong," said the Briton, whose team were runners-up last year.
"You'll see big increments early on because the regulations are pretty immature. I think there is going to be low-hanging fruit early on to make sizeable steps.
"That's going to push every department in the whole team to try and outwit, out-smart, out-develop and out-produce our rivals. That's going to be a stellar challenge in F1 this year."
Red Bull will show off their new car on Sunday with testing starting in Barcelona next Monday.
Horner said former champions Red Bull were on schedule, proceeding like a swan while paddling frantically beneath the surface.
"It's an exciting moment, to see the car break cover," he said. "People get sucked into who's doing what times, which fuel loads, who's doing race runs etcetera...It's all irrelevant in reality.
"You have to focus on your own programme, put the blinkers on, get through your programme of work and the developments you want to look at - because it's all going to change by the time you get to Melbourne anyway."
Renault will launch their own car in London on Tuesday.