Red Seal Automotive Service Technician Practice Exam – Practice Test & Study Guide

The recommendation to replace an oil filter at every oil change is rooted in the role the filter plays in maintaining engine health. The oil filter's primary function is to remove contaminants from the engine oil, which can include dirt, metal particles, and combustion byproducts. Over time, as the engine operates, these contaminants can build up in the filter, leading to reduced oil flow and potentially causing the filter to become clogged.

By changing the oil filter every time you change the oil, you ensure that the new oil remains clean and free from debris, allowing it to properly lubricate the engine components. This practice helps maintain optimal engine performance and longevity, ultimately preventing more serious issues that could arise from using old, contaminated oil.

Other frequency suggestions, such as changing the filter every 5,000 km or every 10,000 km, may vary based on driving conditions and manufacturers’ recommendations but do not take into account the comprehensive preventative maintenance practice of pairing filter changes with oil changes. Not changing the filter at all during an oil change can lead to poor oil quality and reduced engine protection.