Formula 1: Red Bull launches new RB13 car for 2017

Red Bull has unveiled the car many expect to be the closest challenger to world champions Mercedes in 2017.

The RB13 was revealed in a short film on the team's social media outlets and strongly resembles last year's car, the only one to beat Mercedes in 2016.

Designed to the new 2017 rules that will make the cars faster and more demanding for drivers, it has many of the design cues seen on other new cars.

There is also a unique hole in the nose tip, the purpose of which is unclear.

Red Bull driver Daniel Ricciardo, who won the Malaysian Grand Prix last year and finished third in the championship behind Mercedes drivers Nico Rosberg and Lewis Hamilton, said: "It looks quite beautiful. It definitely looks sleek. They look like the fastest cars in the world. That was the impression I got."

Team-mate Max Verstappen, winner in Spain last year and fifth overall behind Ferrari's Sebastian Vettel, said: "The car looks very aggressive. Hopefully when it looks that aggressive it will be fast, but we still have to wait and see."

Like all 2017 cars bar the Mercedes, the Red Bull features a 'shark fin' on the rear bodywork, which provides an aerodynamic advantage in cornering.

The Mercedes ran without a shark fin at its launch day at Silverstone last Thursday but is expected to feature one in pre-season testing, which starts on Monday.

The angle of the Red Bull shown in the video did not allow sight of what are expected to be a complicated and intricate series of airflow conditioners behind the nose, in between the front wheels and beside the cockpit, which enhance aerodynamic downforce.

Despite the superficial similarity to last year's Red Bull, the team appear to have packaged the rear bodywork much more tightly to aid airflow at the back of the car.

It is suspected that the car was launched without many of its aerodynamic parts, which it will run in testing.

Can they catch Mercedes?

There is great expectation surrounding Red Bull for 2017, with many hoping they can make a fight of it with Mercedes.

Their chassis was pretty much there with the silver cars in 2016 and it would be a surprise if that was not the case again this year - Red Bull were the team who best interpreted the last major chassis rule change, dominating from 2010-13, after Brawn won their title in 2009 thanks to the double-diffuser controversy.

The new car looks the business, in Red Bull style, even if many of the flourishes that are expected were missing on launch day.

In Daniel Ricciardo and Max Verstappen they have one of the best driver line-ups on the grid - one with potential volatility to match the stellar talent.

But the big question mark is over the Renault engine. If that can get close to Mercedes on power, Red Bull might be a serious threat. If not, another season of not-quite-there promises.