How Does Oil Film Form on Car Windows?

[EmmanuelFitz]

The causes of oil film formation on car windows are as follows: 1. Vehicle exhaust: Primarily from vehicle exhaust, which contains various pollutants due to incomplete combustion. Frequent traffic congestion in urban areas, especially when driving behind trucks, inevitably leads to these pollutants adhering to the car windows, forming an oil film. 2. Cooking fumes: Next is pollution from cooking fumes. If the car is often parked near restaurant chimneys, over time, a significant amount of grease and dirt accumulates. If not cleaned promptly, it can form a thick layer of oil residue. 3. Insect remains, bird droppings, and tree resin: Insect remains and bird droppings are highly corrosive. If left uncleaned on the glass, they harden and adhere, affecting the glass's transparency and even turning into an oil film. Additionally, tree resin is another factor. Cars frequently parked under trees may be coated with tree sap or fruit residues, leading to oil film formation.