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What oil looks like when it needs to be changed?


Oil is a vital fluid for keeping your car’s engine running smoothly. It lubricates moving parts, keeps the engine cool, and helps seal combustion chambers. Over time and through normal use, oil picks up contaminants from combustion and wears down. Dirty, worn oil can’t protect your engine as well as fresh, clean oil. That’s why it’s important to change your oil and oil filter regularly. But how do you know when it’s time for an oil change? Here’s what to look out for:

Oil Level

One of the easiest ways to check if your oil needs changing is to look at the oil level on the dipstick. Every car has a dipstick that shows the oil level. To check it:

  1. Park your car on a level surface and let the engine cool completely.
  2. Pop the hood and locate the oil dipstick – it’s usually near the front of the engine with a bright yellow or orange loop ring.
  3. Pull out the dipstick, wipe it off with a clean rag, then reinsert it all the way.
  4. Slowly pull the dipstick back out and examine the level. There should be two marks indicating the minimum and maximum levels.

If the oil level is at or below the minimum mark, it’s time to add oil. If it’s above that mark, the level is ok. But just having enough oil doesn’t mean it’s still good – keep reading for other signs you need an oil change.

Oil Color

Pay attention to the color and texture of your oil next time you check the dipstick. Fresh oil is clear with a honey golden color. As oil gets used, it turns darker and may start to look dirty brown or black.

Thick, sticky oil that is very dark brown or black has too many contaminants and needs changing. It will leave dark, black carbon deposits on the dipstick too.

Lighter oil isn’t necessarily cleaner. Some synthetics maintain a lighter color but still need to be changed at regular intervals.

Oil Smell

Take a whiff as you check the dipstick. Oil has a distinct petroleum smell when fresh. As it wears, you may notice a burnt smell, which could indicate engine problems. A very strong gasoline or fuel smell means fuel is leaking into the oil, which requires prompt attention.

Oil Leaks

Keep an eye out for leaks around the engine and under your car. Small leaks may not be cause for alarm. But significant drips or puddles on the ground over a day or two can signal dangerously low oil levels. Leaks need to be inspected and repaired, and the oil topped off or changed if needed.


Most automakers recommend changing oil every 5,000-10,000 miles. But some modern synthetics can go 15,000 miles or even 1 year between changes. Check your owner’s manual for specifics. If you haven’t changed the oil for the recommended interval, it’s overdue regardless of how it looks.

When in Doubt, Change It

Regular oil changes are cheap insurance for engine health. If it’s been several months or you’ve put more than 5,000 miles on the current oil, don’t take chances. Just change it. The small cost of a new filter and fresh oil now can prevent very costly repairs down the road.

Signs of Worn Oil

Here are some key signs that your engine oil has broken down and can no longer protect your engine properly:

1. Change in Oil Color

– Fresh oil has a clear, golden color
– With use, oil turns dark brown or black
– Thick, sticky texture
– Black carbon deposits on the dipstick

2. Change in Oil Smell

– Fresh oil has a mild petroleum smell
– Worn oil smells burnt or fuelish

3. Low Oil Level

– Oil at or below the minimum “Add” mark on dipstick indicates low level
– Significant leaks can also cause low oil

4. High Mileage

– Oil should be changed every 5,000-10,000 miles
– Exceeding manufacturer’s recommended interval means it’s overdue

Key Takeaways

– Check oil level, color, smell, leaks regularly
– Dark, dirty oil needs changing
– Burning smells signal mechanical problems
– Fix any leaks immediately
– Change oil at least every 5,000-10,000 miles

How Often Should You Change Engine Oil?

Most automakers recommend changing engine oil every 5,000-10,000 miles. But some newer oils and engines can go longer between changes. Here are some general guidelines:

Conventional Oil

Change every 3,000-5,000 miles or 6 months. This is the typical interval for older vehicles.

Synthetic Blend Oil

Change every 7,500-10,000 miles or 12 months. Synthetic blends last longer than conventional oil.

Full Synthetic Oil

Change every 15,000 miles or 1 year. Full synthetics have the most endurance.

High Mileage Vehicles

Change at 5,000 miles or 6 months. Shorter intervals help remove more contaminants.

New Vehicles

Follow manufacturer’s recommended interval, usually around 10,000 miles. Check owner’s manual.

Extreme Conditions

Change more frequently, every 3,000-5,000 miles. Frequent short trips and very hot or cold weather require more changes.

What Type of Oil Should You Use?

What kind of oil is best for your car? Here are some tips:

Check Owner’s Manual

Follow the viscosity and performance rating recommended for your vehicle. This is usually 5W-20, 5W-30, or 10W-30.

Conventional vs. Synthetic

Synthetics last longer but cost more. Use conventional if you change oil regularly. Go synthetic for max intervals.

Match Driving Conditions

Heavier oils like 10W-30 are good for high temps and hauling heavy loads. Lighter weights like 5W-20 improve fuel economy.

Quality Ratings

Look for oils that meet API SN Plus or SP performance standards. These formulas protect modern engines.


Major brands like Mobil, Castrol, Valvoline are proven reliable choices. Check Consumer Reports ratings.


High mileage oils have more seal conditioners. Use if your car has over 75,000 miles.

Can You Change Oil Too Often?

Is there any downside to changing your oil more frequently than recommended? Here’s what you need to know:

No Harm in Changing Early

It won’t damage your engine to change oil sooner than required. The only risk is spending more money on unnecessary oil changes.

Depends on Oil Used

Conventional oil needs more frequent changes. But synthetics are designed to last the full interval.

Mileage is Key

Time alone doesn’t wear oil much. The recommended intervals are based on average mileage.

Check Manufacturer Specs

Follow the maintenance schedule in your owner’s manual, not the quick-lube shop trying to sell services.

When in Doubt, Change It

If you can’t remember the last oil change, or exceed mileage by a few thousand, it won’t hurt to change early for peace of mind.


Checking oil level, color, smell, and leaks regularly makes it easy to identify when it’s time for an oil change. Dark, sludgy oil and a burnt smell are key indicators. Most engines need fresh oil every 5,000-10,000 miles. While changing early does no harm, follow manufacturer specifications for your driving conditions. Proper oil changes keep your engine running smoothly for the long haul.


Here are answers to some frequently asked questions about changing engine oil:

How often should I change my oil?

Most automakers recommend oil changes every 5,000-10,000 miles. Check your owner’s manual for the interval recommended for your vehicle.

What happens if I don’t change my oil for too long?

Dirty oil can’t properly lubricate and cool the engine, leading to increased wear on internal parts. Prolonged use of old oil can eventually cause engine damage or failure.

Can I change oil too often?

Changing oil more frequently than needed won’t harm your engine, but it will cost you more money on unnecessary oil changes. Follow the manufacturer’s recommendations.

What type of oil should I use?

Check your owner’s manual for the recommended viscosity, usually 5W-20, 5W-30 or 10W-30. Quality standards like API SN Plus help choose a formula that protects your engine.

Do oil additives help?

Additives that claim to clean or recondition worn oil are typically ineffective and not needed with modern oils and proper change intervals. Just use quality oil.

Key Takeaways

– Check oil level, color and smell regularly
– Dark, dirty oil needs changing
– Follow manufacturer’s recommended change intervals
– Changing early does no harm but costs more
– Use the oil weight and quality recommended for your vehicle
– Proper oil changes prevent engine wear and extend service life