Driving to Col du Piéfroid: A brutal 18% 4x4 climb in the Isère Alps
Col du Piéfroid is a high mountain pass at an elevation of 2,937 meters (9,635 feet) located in the Isère department of southeastern France, accessed via an unpaved service track that starts from Col de Sarenne.
| Location | Isère, France (Rhône-Alpes) |
| Elevation | 2,937 m (9,635 ft) |
| Length | 6.0 km (3.7 miles) |
| Elevation Gain | 1,105 m (3,625 ft) |
| Average Gradient | 18.41% |
| Surface | Unpaved / Loose scree and shale |
How challenging is the 18% climb to Col du Piéfroid?
The climb gains 1,105 meters of vertical elevation over just 6 km, resulting in a continuous average gradient of 18.41%. The surface consists of loose alpine scree and sharp stones where losing momentum spins tires into shale, requiring low-range 4x4 engagement throughout the ascent. It's one of the highest roads in Europe.
What are the hazards of the Piéfroid track?
The track is an unmaintained chairlift access trail with exposed drops and steep side slopes. Snow buries the pass outside summer months, while rain transforms the shale dust into mud, causing traction loss on 18% gradients.
What is the driving strategy for Col du Piéfroid?
Engine output drops near 3,000 meters due to low oxygen levels, making power management critical through tight turns. Descending the 18.41% grade requires low gears to engine-brake the vehicle, avoiding foot-brake overheating on loose stone slopes. It's one of the highest roads of France.