Warning: Skipping an Oil Change Can Be Harmful to Your Engine

“I didn’t have time to get it done before my trip.”

“I’ll do it next month.”

“I just forgot.”

These are a few of the many excuses drivers give for skipping an oil change. In some cases, no harm will come from exceeding the recommended oil change interval by a few hundred miles. But because fresh, clean motor oil is so vital to an engine’s longevity, drivers should be very careful to follow recommended schedules for oil changes and other services. In worse-case scenarios, dirty oil can cause serious and costly engine problems.

This is especially true for higher-mileage vehicles like my 2004 Subaru, which currently shows about 133,000 miles on the odometer. Most people know that motor oil is a lubricant that reduces friction between moving internal engine components. But there’s more to the stuff than just reducing friction. Oil also cools and cleans the engine. To do its job properly, motor oil must be effective in all three of these roles.

As oil gets old, it loses viscosity. That simply means it becomes thinner and runnier, reducing its ability to lubricate. It also becomes dirtier as tiny metal shavings worn away from components become suspended in the oil. Even if it retains some cooling properties, the dirty, low-viscosity oil stops effectively cleaning and lubricating internal engine parts.

Filled with tiny metal particles, dirty oil not only fails to do its job of lubricating and cleaning but causes further engine wear. From there, problems compound: oil becomes dirtier, causing more wear, and wear causes oil to become dirtier still.

So while exceeding your vehicle’s recommended oil change interval by a few miles is harmless, going too long without fresh oil and a new filter can cause serious engine damage.

Synthetic motor oil does not lose viscosity like conventional motor oil, so oil change intervals are typically longer for vehicle’s that use it. But synthetic oil still becomes dirtier over time. If your vehicle’s manufacturer recommends synthetic oil, do not substitute conventional oil.

Changing your own oil is easy. In most cases, you just need a few tools, motor oil and a new oil filter.

Oil Change Tools

Wrench for removing oil drain plug
Oil drain pan
Oil filter wrench

Oil Change Supplies

Motor oil (follow manufacturer’s recommendations for motor oil weight)
Oil filter
Drain plug washer

Changing the oil on my car takes about half an hour. Once completed, I simply returned the used oil to my local NAPA AUTO PARTS location for recycling. Never dump used motor oil as doing so is both illegal and harmful to the environment.

Performing a DIY oil change isn’t for everyone. Maybe you don’t have the time, the space or even the interest in doing it yourself. If you prefer to leave oil changes to a professional, your local NAPA AutoCare Center can handle the job.