Daniel Ricciardo is less optimistic and more philosophical about his chances of success with Red Bull this Formula One season, but hopes to be pleasantly surprised.

After winning three races in 2014, the Australian was let down last year by an underpowered and unreliable Renault engine that yielded no victories and just two podium finishes.

With few rule changes for 2016, Ricciardo said he would be working with pretty much what he had last year.

“Sure, we can improve it. But how much we can improve? It is hard to say we’ll get onto Mercedes’ level,” he told Fox Sports in part one of an interview that aired on Thursday night.

“We’re not going to get too optimistic with our chances.

“Last year, we came into it all excited and (saying) ‘Yep, it’ll be a lot better’ and we just sort of got let down.

“Your frustrations become more when you expect so much so I think we’re all just playing it cool for now. Hopefully, we’re pleasantly surprised.”

Renault will have their own team this season after buying Lotus but will still provide Red Bull with engines, albeit with different branding.

It’s of little solace to Ricciardo, who knows he wasn’t even close to challenging for the title last year, given the gap in horsepower with runaway winners Mercedes and their championship-winning driver Lewis Hamilton.

He’s already looking ahead to 2017 in the hope changes to the category will deliver better results.

“The way the whole formula is at the moment, the last couple of years since the V6s have come in and these new power units, it’s sort of created a bit more of a division, I think, between the best and the rest,” said Ricciardo, whose Red Bull contract expires at the end of the season.

“We’ll see how this year goes but, hopefully for 2017, they’re talking about a lot of rule changes, and you just want it to hopefully bring a bit more equality.

“There’s always going to be teams that build a better car, which is fair enough, but – when it’s just pure horsepower from one team to another – it’s a bit frustrating if you’re not in the one with more horsepower.”

Ricciardo also spoke about his bittersweet podium at the 2015 Hungarian Grand Prix, the first race following the death of friend and fellow F1 driver Jules Bianchi.

“It just struck a few more chords (than I expected) … and made me realise … we are risking our lives to be here and to race.”

The 26-year-old will debut Red Bull’s new challenger at next week’s first pre-season test in Barcelona, ahead of the season-opener on March 20 in Melbourne.