Top Gear sets out on perhaps its toughest road trip ever - a high-altitude voyage from Kathmandu, capital of Nepal, to the Forbidden City of Lo Manthang, a secretive kingdom perched high on the Tibetan plateau, on the far side of the Himalayas. It is a five-day expedition through the highest mountains, deepest gorges and harshest terrain on the planet. On their journey, the Top Gear presenters battle river crossings, mudslides and dizzying mountain passes on a trip that would test even the hardiest new 4x4s on the planet to the limit. But Paddy, Freddie and Chris ...

Paddy, Freddie and Chris head on a British summer holiday in super-cheap second-hand convertibles. Chris tests the new Ariel Atom on track, and Freddie attempts to bungee-jump an old Rover off a dam.

Paddy reveals his ultimate cheap, luxurious off-roader: the homebuilt Dirty Rascal. Chris races the £2.5m McLaren Speedtail against the RAF's newest fighter jet. Romesh Ranganathan is the studio guest.

Paddy, Freddie and Chris are sent on a high-altitude mountain expedition across Peru in second-hand American cars. Back at the track, Chris tests out the latest electric car from Porsche.

Freddie and Chris tackle the toughest off-road race on the planet: the brutal Baja 1000. Out on the track, there is a showdown between a Renault hot hatch, a Porsche sports car - and an old Lamborghini. Laurence and Emilia Fox are the studio guests.

Paddy, Freddie and Chris take the latest sports cars from Ferrari, Aston and Porsche on a Yorkshire road trip. On the track, Chris tests out Volkswagen's fearsome ID-R electric racer. YouTube sensation KSI is the studio guest.

Paddy, Freddie and Chris find out which is the fastest of the emergency services. Fire, police or ambulance? Chris celebrates legendary rally driver Colin McRae, while Paddy tests the new BMW M8. Tom Allen is this week's studio guest.