Ojos del Salado was even higher than Ojos del Salado. Later measurements using more precise equipment showed that Ojos del Salado is about higher than Pissis. Furthermore, in 2007 a Chilean–Argentine–European expedition organized by Andes Magazine and Azimut 360 performed a survey on both Ojos del Salado and Monte Pissis using more accurate instruments. It found the former to be and the latter Although this fits within recent handheld GPS surveys, which have estimated the mountain to be between and , the vertical error margin of the expedition's equipment, , leaves uncertainty as to the mountain's more precise altitude. Ojos del Salado has
Ojos del Salado of Ojos del Salado was , but that was "simply [...] based on the altitude of the final camp, and the hours of ascent to the summit." In 1956, the first Chilean expedition led by the retired lieutenant René Gajardo measured the height of Ojos del Salado as with a pocket pressure altimeter. Apart from being an inexact method, the height shown by the altimeter was far too high as air pressure is generally lower in the afternoon, the time at which the team reached the summit. An expedition to the area in the 1990s claimed that nearby Monte Pissis