Is there a relationship between oil emulsification and driving distance?
3 Answers
Oil emulsification is related to driving distance. Long-distance driving at medium to high speeds can slow down or eliminate the phenomena of oil dilution and emulsification. When the engine temperature rises, it promotes the evaporation of water within the oil, causing the emulsification to disappear. Engine oil emulsification can generally be divided into two categories: oil filler cap emulsification and oil pan emulsification. Below is a detailed introduction: The cause of the former is relatively common. Frequent short-distance driving in winter can prevent the engine from operating at normal working temperatures for extended periods, leading to ineffective dispersion of moisture, which then condenses on areas like the oil filler cap. This moisture mixes with oil droplets adhering to these areas, forming an emulsion. The latter occurs when a significant amount of water mixes into the oil. There are many causes for this, such as water from the engine heat exchanger entering the oil due to poor sealing, water entering the oil during combustion, or moisture reflux caused by failures in the oil-gas separator and PCV valve, among others.
I've been repairing cars for nearly a decade and frequently deal with oil emulsification issues. Honestly, it's related to driving distance. Short trips, like commuting just a few kilometers, don't allow the engine to warm up sufficiently, preventing the moisture in the oil from evaporating, which then mixes and turns white, causing emulsification. This is especially true in winter when stopping and starting frequently leads to more water accumulation. On the other hand, long-distance driving heats the engine thoroughly, and after about 20 minutes, the water evaporates, significantly reducing emulsification. I recommend car owners take at least one highway trip each month to keep the oil dry. Severe emulsification can damage engine seals, leading to costly and labor-intensive repairs. Regularly check the dipstick, and if you notice discoloration, change the oil promptly.
I mostly drive short distances in the city, and last winter I noticed my engine oil had emulsified. Upon inquiry, I learned that water had mixed in. Short trips mean the engine warms up slowly, allowing water vapor to condense and accumulate; in contrast, long drives heat up the engine enough to evaporate the moisture. Since then, I make a point to drive at least 30 kilometers on the highway each week, and the oil has become clear again. This issue is more common in cold regions, especially for electric vehicles, but it also affects gasoline cars used for short trips. Prevention is simple: warm up the engine before driving or extend your driving intervals. Emulsification reduces lubrication and increases wear, which is not worth the risk.
