Ruta Provincial 40 Paso de San Francisco

Stock high-clearance 4WD is the minimum — a bone-stock Tacoma or 4Runner can physically make it, but you want good all-terrain tires, a full-size spare, and ideally recovery gear. The surface is rough Andean gravel with washboard sections, and at 15,500 ft your engine loses roughly 40% power, so anything with a weak tune or marginal tires is going to hurt you.

Best window is November through April (Southern Hemisphere summer). Outside that, snowfall and ice at the 4,726-meter summit can close the crossing entirely with zero warning — Gendarmería will turn you around. Even in peak season, afternoon storms are common; plan to hit the summit in the morning.

Yes — this is a functioning international border crossing managed by Gendarmería Nacional Argentina on the Argentine side. You need a valid passport, your vehicle's title or registration, and a vehicle exit permit (Permiso de Salida) issued by AFIP if the car isn't in your name. The Chilean side at Paso San Francisco has SAG agricultural inspection — declare everything. Cross outside staffed hours and you're not getting through.

The climb to the summit pass itself is the crux — steep, loose volcanic gravel, no guardrails, significant exposure on the edge, and serious altitude-related power loss hitting all at once. At 15,500 ft, AMS (acute mountain sickness) is a real risk for drivers and passengers who haven't acclimatized; don't come straight from sea level. There's also zero cell service and virtually no traffic if something goes wrong.

Fiambalá is your last reliable fuel stop before heading out — fill to the absolute brim, as it's roughly 200 km to the Chilean side with nothing in between. There are some small streams at lower elevations, but treat everything and don't count on it; carry at minimum 10 liters of water per person for the crossing.