Chris Evans has admitted to being scared while filming a segment for the new Top Gear that involved racing to the highest pub in South Africa.
The popular motoring show returns on Sunday boasting a new presenting line-up including Friends star Matt LeBlanc and four other hosts, including German racing driver Sabine Schmitz, plus The Stig.
The new series of the BBC Two show has been filmed over four continents in nine countries.
Evans said: "We ended up on this nine mile pass, that goes three thousand metres (above sea level) ... that was scary, there was nothing, it was a loose gravel road and we were going as fast as we could and it was getting dark because we were late filming."
The segment sees the team - joined by singer Tinie Tempah, Seasick Steve and Texas's Sharleen Spiteri - putting the latest SUVs from Porsche, Jaguar and Mercedes-Benz through their paces with the aim of getting to the pub to headline a gig.
The former TFI Friday presenter dubbed his co-host, LeBlanc, Mr Top Gear, saying: "He is built for this programme, literally."
His "wing man" was absent from the global launch of the show earlier in the week, but sent a video message explaining that he was busy filming the final series of his BBC TV show, Episodes.
LeBlanc said: "It's great that the show continues to prompt so much global interest, even before we have shown the first episode. I've had an amazing and crazy few months since joining Top Gear. We've accomplished a lot and I'm extremely proud of it."
The duo has been plagued by reports that they are at loggerheads, but LeBlanc recently dismissed the reports, calling them bullshit.
When the series airs on Sunday night, viewers will see the newly-launched Star In A Rallycross Car, which replaces the show's old Star In A Reasonably Priced Car segment.
It features a new car and new track, as well as seeing two celebrities going head to head. The first guests this weekend are the Social Network star Jesse Eisenberg and chef Gordon Ramsay.
Evans explained changes to the new format using a football analogy.
He said: "It's like taking over a football club and saying we're going to get rid of the goals... we're going to get rid of the ball and we might change the grass.
"That's what people come for, so you keep all that stuff and if something is getting a bit tired you dispense with that, but the fact that the studio is slightly different, the fact that the presenting team is slightly different, is enough in a way, that's a massive change."
The new set has raised viewing platforms on either side, a balcony, and a new viewing wall. Evans also revealed that interview segments would be shorter, saying: "We're going to get on the to cars as fast as we can.
"Andy Wilman, who used to make the show, used to say they make it for a nine-year-old. That's a great philosophy because kids get bored really quickly. But that doesn't mean they have a short attention span if it's interesting, so you've got to make it interesting and things have to move. So we have this rule that you've got to move it in 15 seconds."
Ex-Formula 1 team boss Eddie Jordan, YouTuber Rory Reid, motoring journalist Chris Harris and The Stig complete the full presenting line-up.
Reid will front spin-off show, Extra Gear, which will be available on BBC Three immediately after the main show, and will "give people more of what they've seen on the main show."
:: Top Gear returns to BBC Two on May 29 at 8pm.