Three Range Rover Hybrids have completed a 10,472-mile trek from the UK to India.
The journey, which followed the Silk Trail through Europe and the Middle East, took in 13 countries and two continents along its route, and took 53 days in total.
Temperatures ranging from -10C to 43C and altitudes of up to 5,500 metres (18,045 feet) tested the three prototype vehicles to their limits.
The Land Rovers were also the first foreign-registered vehicles to travel along the Xinjiang-Tibet highway.
Land Rover says that the Silk Trail expedition was the final validation test for its new Range Rover Hybrid, intended to fine-tune the calibration of engine and transmission software on all terrains and at all altitudes before the model is signed off for production.
The new model will feature a combination of a 3.0-litre V6 turbodiesel engine, supported by a 35kW electric motor, with the aim of reducing the Range Rover's emissions and fuel consumption while still retaining power.
Land Rover adds that the Range Rover Hybrids typically returned 36 to 37mpg on the demanding route.
In total, the convoy of three Hybrids and four support vehicles suffered 15 punctures, four wheels damaged by deep potholes, and four windscreens cracked by stones being thrown up.
"In developing the hybrid-powered Range Rover, our objective was to gain hybrid's fuel economy and carbon emission advantages without compromising the Range Rover's go-anywhere capabilities, its cabin space or its refinement," said Peter Richings, Jaguar Land Rover's Hybrids & Electrification Director.
"The success of this remarkable expedition clearly demonstrates we have achieved that."