Here's why:
* Compatibility Issues: Mineral-based lubricants are not compatible with the synthetic refrigerants used in most modern vehicles. These refrigerants, like R-134a and R-1234yf, can cause mineral oil to break down, leading to sludge formation and system damage.
* Performance Concerns: Mineral oils have a lower viscosity and evaporating point compared to modern synthetic lubricants. This can lead to poor lubrication, increased wear, and reduced system efficiency.
Modern mobile AC systems primarily use synthetic lubricants, specifically PAG (polyalkylene glycol) oils. These oils are specifically designed to be compatible with modern refrigerants and offer superior performance and protection.
Older vehicles that still use R-12 refrigerant may still use mineral oil, but even those systems are increasingly being converted to newer refrigerants and synthetic lubricants.
It's crucial to always consult the vehicle manufacturer's specifications and use the recommended lubricant for the specific AC system.