Max Verstappen is convinced Red Bull would have mounted a title challenge this year with an engine to match Mercedes and Ferrari.

In a wide-ranging interview which airs in Sky F1's exclusively live coverage of Sunday's Brazilian GP on Sunday from 3.30pm, Verstappen says Renault-powered Red Bull's 2018 chassis has clearly shown itself to be a match for their two main rivals.

"Let's say it like this: if we had the same power as Mercedes and Ferrari we would have definitely challenged for the title," Verstappen said.

"There is no doubt about that because you can see as soon as we go to a track where the engine is not as important as other tracks, we are always fast.

"So there is no excuse. We are not lying; there are facts that our car is good, we are just really down on power."

A case in point was the recent Mexican GP at the highest-altitude track of the season when the team locked out the front row and Verstappen comfortably won the race.

Although the team credited Renault for the engine's performance in the unique conditions, Red Bull largely feel the French manufacturer's product has held them back since the hybrid era began in 2014.

In an attempt to get back to title-contending ways in future seasons, Red Bull are switching to Honda engines next year in a partnership that is exclusive to them and junior team Toro Rosso.

Asked if they can challenge the top two in 2019, a cautious Verstappen replied: "I hope, but you always have to wait and see if we build a good car again. At the moment I'm not looking forward to next year, I'm just looking forward to having a break first and then getting fully ready for the year coming.

"But if everything works out well and what we see from the numbers on the dyno and everything, then I'm sure that at one point in the season we can definitely fight for more victories."

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