The new McLaren W1 has now completed its rigorous Arizona hot-weather sign-off: the ultimate validation for high-temperature durability. This programme pushes the car to extremes that mirror real-world customer use. 5,000 km of testing and hundreds of hours on both road and track, with ambient temperatures exceeding 100°F (38°C). Repeated 0–200 km/h full-throttle acceleration cycles, followed by aggressive braking, to confirm cooling efficiency and powertrain resilience. Extended open-road evaluations to validate air-conditioning performance and thermal stability under prolonged heat soak. The verdict? The W1 passed every challenge with flying colours, sustaining long track stints while maintaining full driver comfort. This milestone confirms that the W1 is engineered to perform - wherever the road leads.