What Causes High Altitude Sickness in Cars?

[SanAlessandra]

High altitude sickness in cars is caused by discomfort due to decreased air pressure and reduced oxygen levels. Symptoms of high altitude sickness in cars: Insufficient power; excessively high brake oil temperature; excessively high water temperature; engine stalling. Methods to address high altitude sickness in cars: Inspect the cooling system in advance and avoid using antifreeze containing alcohol; frequently monitor water temperature and take breaks when necessary; use a high-performance oil pump. High altitude sickness in cars occurs due to the external environment of low air pressure and oxygen levels in high-altitude regions. As vehicles travel deeper along the Sichuan-Tibet line, the increasing altitude leads to thinner air. With the continuous drop in air pressure, the oil pump may experience fuel cutoff, causing the engine to stall.

[McKylie]

The main reason for cars experiencing altitude sickness is the low oxygen content in the high-altitude air. Above 2,000 to 3,000 meters, the air becomes thinner, and the engine doesn't get enough oxygen to burn fuel efficiently, much like how people gasp for breath when climbing mountains. My off-road vehicle struggled to climb the Zheduo Mountain—even with the accelerator floored, the RPM wouldn't rise, and black smoke came out of the exhaust. Turbocharged cars fare slightly better since the turbo can force more air into the engine. Naturally aspirated cars suffer the most, especially those with small displacements below 2.0L—overtaking becomes a real test of patience. Before heading to high-altitude areas, it's advisable to clean the throttle body and replace the spark plugs to help the engine breathe more smoothly.

[AnnieLynn]

The higher the altitude, the weaker the engine becomes. I learned this firsthand during my self-drive trip to Tibet last year. The BMW X1 in our group felt like stepping on cotton when accelerating up the 72 Hairpin Turns of the Nujiang River. The principle is simple: reduced air density leads to insufficient engine intake, incomplete fuel combustion, and naturally diminished power. Some cars' ECUs automatically adjust the air-fuel ratio, but above 4,000 meters, they all basically lose steam. An experienced driver shared a trick with me: before climbing, switch to manual mode, downshift to raise the RPM—it might be noisier, but it works better than just flooring the gas pedal.

[ChloeDella]

The sluggish power when driving on plateaus is essentially due to insufficient oxygen. For every 1,000 meters increase in altitude, the engine power decreases by about 10%. This was particularly noticeable when I drove a naturally aspirated car in Shangri-La—the throttle response was noticeably delayed. Turbocharged cars perform better as the turbocharger forces more air in, but high altitudes also take a toll on the turbo. To mitigate this, you can use higher-octane fuel in advance to prevent knocking and replace the air filter to reduce intake resistance. If you plan to drive over a 5,000-meter-high mountain pass, consider flashing a plateau-specific ECU program to optimize the air-fuel ratio.