What Happens If You Use a Smaller Oil Filter(7 Warnings)

Your car’s engine is a complex machine with countless moving parts. Each component plays a crucial role in ensuring optimal performance and longevity. One often overlooked yet critical component is the oil filter. It’s the unsung hero that diligently cleanses your engine’s lifeblood, the oil. But what happens if you decide to cut corners and use a smaller oil filter?

What Happens If I Use a Smaller Oil Filter

What Happens If You Use a Smaller Oil Filter

1. Reduced Oil Filtration Efficiency

One of the primary concerns with using a smaller oil filter is the potential reduction in filtration efficiency. Oil filters are designed with a specific surface area for trapping contaminants. A smaller filter has less filter media, meaning it can hold fewer contaminants before becoming clogged.

This limited capacity can lead to quicker saturation of the filter, reducing its ability to effectively clean the oil. As a result, dirty oil may circulate through the engine, increasing the risk of damage and wear.

2. Impact on Oil Flow Rate

The oil flow rate is another critical factor affected by the size of the oil filter. An engine requires a specific flow rate to ensure proper lubrication of its moving parts. A smaller oil filter may restrict the flow of oil due to its reduced surface area and internal design.

This restriction can lead to a drop in oil pressure, resulting in insufficient lubrication. In severe cases, this can cause metal-on-metal contact within the engine, leading to increased friction, heat, and potential engine damage.

3. Increased Risk of Oil Bypass

Most oil filters come equipped with a bypass valve, a safety feature that allows oil to bypass the filter if it becomes clogged or if the oil is too thick at cold temperatures. This ensures that the engine still receives oil, even if it is unfiltered.

However, a smaller oil filter is more likely to reach its capacity and trigger the bypass valve prematurely. This means that unfiltered oil, containing contaminants, can circulate through the engine, increasing the risk of wear and damage over time.

4. Shortened Oil Filter Life

A smaller oil filter will generally have a shorter lifespan compared to the recommended size. Due to its limited capacity, it will reach its maximum holding potential faster, necessitating more frequent replacements.

If not replaced timely, a clogged filter can significantly impact engine performance and health. Regularly replacing oil filters is essential, but using an undersized filter can complicate maintenance schedules and increase the risk of engine issues.

5. Compatibility and Fitment Issues

Another concern when using a smaller oil filter is compatibility and fitment. Oil filters are designed to fit specific engines and models. Using an incorrect size can result in improper sealing, leading to oil leaks.

A filter that is too small may not fit securely, causing oil to escape and potentially damaging the engine. Moreover, mismatched threading or sealing can prevent the filter from properly attaching to the engine, risking detachment during operation.

Read How Tight Does an Oil Filter Need To Be(Avoid This Mistake)

6. Effects on Engine Performance

Engine performance can suffer when using an undersized oil filter. The reduced oil flow and filtration efficiency can cause an increase in engine wear and tear. Over time, this can lead to a loss of power, reduced fuel efficiency, and increased emissions.

Also, the engine may become noisier due to inadequate lubrication and the resulting friction between moving parts. For those who prioritize their vehicle’s performance, sticking to the recommended oil filter size is crucial.

7. Potential for Long-Term Engine Damage

The long-term effects of using a smaller oil filter can be severe. Consistently using a filter that does not meet the engine’s specifications can lead to a buildup of contaminants, increased friction, and overheating.

These issues can cause significant damage to engine components, potentially leading to costly repairs or even engine failure. In some cases, warranty coverage may be voided if improper maintenance, such as using the wrong oil filter, is determined to be the cause of engine issues.

How to Choose Right Oil Filter

To protect your engine investment, it’s essential to use the correct oil filter.

  • Consult your owner’s manual: This document specifies the exact oil filter size and type recommended for your vehicle.
  • Choose a reputable brand: Quality oil filters are designed to meet specific performance standards.
  • Regular oil changes: Adhere to your vehicle’s recommended oil change intervals to maintain optimal engine health.

Read How to Clean Funnel After Oil Change(Don’t Make These Mistakes)

Final word

Using a smaller oil filter than recommended can have significant and potentially harmful consequences for your engine. The downsides far outweigh any perceived benefits from reduced filtration efficiency and oil flow issues to the increased risk of long-term damage.

Following the manufacturer’s recommendations for oil filter size and type is essential to ensure optimal engine performance and longevity. 

Ryan Gary
Ryan Gary

With a solid foundation of 20 years in the mechanical industry and a Mechanical Engineering degree, Ryan Gary brings a deep understanding of automotive systems to Engine Oil Journal.
Driven by a passion for vehicles and a commitment to providing accurate information, he created this platform to empower drivers to make informed decisions about engine oil care.

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