RED Bull star Max Verstappen delivered a scathing appraisal of his own team after he failed to finish the British Grand Prix.

The Dutch driver described his team’s Renault power unit’s performance as “tragic” and a “joke” after Red Bull suffered a disastrous weekend at Silverstone where their only championship points came through Aussie Daniel Ricciardo’s fifth-placed finish.

Verstappen’s race ended after he spun out as the result of a brake-by-wire malfunction which caused clutch damage. After spinning out, Verstappen was unable to get his Red Bull out of first gear because of the clutch problem.

He said the technical difficulties should not distract from the complete disaster Red Bull experienced in straight-line speed.

“I tried to do a one-stop (strategy). In the end I was lucky that there was a safety car, because that wasn’t going to work,” Verstappen told Dutch television, according to motorsport.com.

“After the first safety car I made that move on Kimi (Raikkonen), which was nice, but it’s just incredibly frustrating how much we are lacking on the straights. It’s a real bummer.

“It was tragic. On the straights it’s like you are driving in a different series.”

Red Bull boss Christian Horner admitted it was a bad day for his team — but declared the poor performance of the Renault power unit vindicates his decision to switch to Honda-supplied engines for the 2019 and 2020 seasons.

The struggling Renault engine crippled Ricciardo’s late charge to try and overtake Mercedes driver Valtteri Bottas, despite the Finnish racer running on older tyres, Skysports.com reports.

According to Horner, Ricciardo continued to lose straight-line speed to the Mercedes even when benefiting from DRS.

“You could see how exposed we are in a straight line,” said Horner.

“We were hugely exposed both in attack and defence.

“In qualifying, we were quicker than Sebastian (Vettel) in every single corner but we just hosed time down the straights.”

And Verstappen added: “When we had DRS open we were going the same speed as the Mercedes and Ferraris without DRS, so you can’t do anything.

“You could see all the time behind the Safety Car when we were drag racing, we were so slow. It was a joke.”

Red Bull have signed a two-year deal with Honda for 2019 and 2020 after wearying of Renault’s struggles in F1’s current era of hybrid power when pitched against Ferrari and Mercedes.

Although Toro Rosso, Red Bull’s sister team who currently use Honda power, also believed they lost around a second per lap because of their relative power deficiency at Silverstone, Horner is adamant Red Bull are right to switch engine suppliers.

“Both engines are very similar at the moment but it is all about the potential development,” he said.

“This weekend has been very tough for Renault. You can’t hide behind the statistics of what we have seen this weekend. There is a gap to fill and hopefully with Honda…we have a lot of belief in what they have in the pipeline.

“The reality is that it is the time to change. We have been doing the same thing for year after year. We are seeing real progress with Honda. It feels the right time in our evolution to go in a different route.”

Horner also added he now suspects Ferrari boast the most powerful engine on the grid. “I think they are the benchmark now,” he said.