2018 Toyota Highlander 3.5: Exact Oil Capacity

If you're looking up the 2018 toyota highlander 3.5 oil capacity, you're probably planning an oil change. That's a solid move. Keeping the right amount of the right oil in that 2GR-FKS engine is one of the simplest ways to make it last well past 200,000 miles.

Manufacturer specifications indicate that the 2018 Highlander 3.5 takes exactly 6.4 US quarts of 0W-20 synthetic oil when you also replace the oil filter. That's 6.0 liters for those using metric. Get this number wrong, and you risk everything from poor fuel economy to internal engine damage.

Let's walk through exactly what you need to know.

Image source: Bing (Web (fair-use with source credit))

Quick Answer: How Much Oil Does a 2018 Toyota Highlander 3.5 Take?

The 2018 Highlander 3.5 takes 6.4 quarts of oil. That's with a filter change included. Without a new filter, it's 6.0 quarts.

Use 0W-20 synthetic oil. That's the short answer.

The 2GR-FKS Engine: What Makes This Engine Different

The 2018 Highlander's 3.5-liter V6 isn't just any engine. It's Toyota's 2GR-FKS, a workhorse that also appears in the Sienna, the RX350, and several other Toyota and Lexus models. This engine uses both port injection and direct injection.

That dual-injection system helps keep carbon buildup low on the intake valves, which is a common headache on many direct-injection-only engines.

What does that mean for your oil change? The 2GR-FKS has tight tolerances. It's designed around 0W-20 oil for a reason.

That thin oil flows quickly at startup, reaching critical components like the timing chain and variable valve timing actuators almost instantly. Heavier oil can delay that flow, causing extra wear over time.

This engine also has a specific oil filter location. It's mounted on the front of the engine block, accessible from underneath the vehicle. That makes it easier to reach than some other Toyota engines where the filter is buried.

Still, you need the right tools and preparation.

A quick note on the engine's oil capacity history. The 2018 model year is part of the third-generation Highlander, which ran from 2014 to 2019. The 3.5-liter V6 in this generation kept the same 6.4-quart capacity throughout.

Later models, starting with the 2020 redesign, moved to a different engine platform with different specs. So if you're working on a 2018, these numbers are locked in.

For reference, the 2GR-FKS engine in this generation shares some design traits with the smaller engines found in other Toyota models. If you're curious about how the oil specs compare, you can check out the oil type guide for the Toyota RAV4 or the 2025 Camry Hybrid oil type recommendations. Each engine has its own specific needs.

Oil Capacity Specs: With Filter vs. Without Filter

This is where a lot of DIYers get tripped up. The oil capacity number changes depending on whether you're replacing the oil filter or not. Here's the breakdown:

The "with filter" number is the one you should use for a standard oil change. The filter itself holds about 0.4 quarts of oil. If you skip the filter change, you're overfilling by that amount if you pour in the full 6.4 quarts.

Why does this matter? Overfilling by even half a quart can cause the crankshaft to whip the oil into a froth. That foam doesn't lubricate properly.

Air bubbles in the oil can lead to reduced oil pressure and accelerated wear on bearings and camshafts. We've seen engines with foamed oil develop knocking sounds within a few thousand miles.

The "engine dry" number is for a completely empty engine block, like after a full rebuild or replacement. You'll never need that number for a routine oil change. Stick with 6.4 quarts with a new filter, and always check the dipstick after filling.

If you're servicing other Toyota vehicles, the capacities vary. The 2024 Tacoma oil type guide covers a different engine, and the 4Runner oil type guide has its own specs. Always verify for the specific model.

What Type of Oil Does the 2018 Highlander 3.5 Need?

Toyota calls for 0W-20 synthetic oil. That's not a suggestion. It's the spec.

The owner's manual for the 2018 Highlander clearly states that the engine requires API SN or newer, ILSAC GF-5 certified oil in 0W-20 viscosity.

Image source: Bing (Web (fair-use with source credit))

Let's break down what those letters mean. API SN is a service category from the American Petroleum Institute. It indicates the oil is designed for high-performance engines with improved sludge protection and seal compatibility.

ILSAC GF-5 is the International Lubricant Specification Advisory Committee standard. It focuses on fuel economy, emissions system protection, and turbocharger protection. The 2GR-FKS needs both.

Can you use 5W-20 or 5W-30? In a pinch, maybe. But it's not recommended.

The 0W-20 oil is thinner when cold, which means it reaches critical engine parts faster on a cold start. That's important for the timing chain and variable valve timing system. Heavier oil might cause the variable valve timing system to respond more slowly, which can affect performance and fuel economy.

Full synthetic is the way to go. Conventional oil doesn't hold up to the heat and stress of the 2GR-FKS as well. Synthetic oil resists breakdown at high temperatures, flows better in cold weather, and keeps the engine cleaner over time.

The price difference is small compared to the cost of engine repairs.

Some owners ask about high-mileage oil for engines with over 75,000 miles. That's fine. High-mileage oil has seal conditioners that can help reduce leaks.

Just make sure it's still 0W-20 and meets the API SN/ILSAC GF-5 standards.

For a complete breakdown of oil types across Toyota's lineup, take a look at the Toyota Highlander oil type guide from our team. It covers the full model range with specific recommendations.

Step-by-Step: How to Check Your Oil Level Correctly

Checking your oil level sounds simple. But doing it wrong can give you a false reading. Here's the correct method for the 2018 Highlander 3.5.

Image source: Web (Bing) / everturtle.weebly.com (Web image (fair-use with source credit))

Step 1: Warm up the engine. Drive the vehicle for about 5 to 10 minutes to get the oil up to operating temperature. Cold oil drains slowly and can give a low reading. Hot oil flows freely and gives an accurate level.

Step 2: Park on level ground. This is critical. Even a slight slope can make the oil pool at one end of the pan. Park on a flat surface and engage the parking brake.

Step 3: Turn off the engine. Wait 5 to 10 minutes. This allows the oil to drain back into the oil pan. Checking immediately after shutdown will show a low reading because oil is still clinging to engine components.

Step 4: Locate the dipstick. It's a yellow loop handle on the passenger side of the engine, near the front. Pull it out completely.

Step 5: Wipe it clean. Use a lint-free rag or paper towel. Wipe the entire length of the dipstick. Insert it back into the tube all the way, then pull it out again.

Step 6: Read the level. The dipstick has two marks: a lower mark for the minimum level and an upper mark for the maximum. The oil should be between those two marks. Ideally, it should be closer to the upper mark.

If it's at or below the lower mark, you need to add oil.

Step 7: Add oil if needed. Use a funnel to add 0W-20 synthetic oil a little at a time. Don't dump in a full quart at once. Add about half a quart, wait a minute, then recheck the dipstick.

Repeat until the level is correct.

One common mistake is checking the oil with the engine running. Don't do that. The oil pump is circulating oil through the engine, so the dipstick reading will be inaccurate.

Another mistake is checking the oil right after adding oil without running the engine. The new oil hasn't reached the pan yet, so the reading might be low.

If you're doing a full oil change, the process is different. We'll cover that in the next section. But for a quick level check between changes, these steps will keep you accurate.

Regular oil level checks are part of good maintenance. The same goes for other Toyota engines. If you own a 2025 Tacoma, the oil type guide for that model has specific recommendations.

And for the Corolla, the 2025 model oil type guide covers the smaller engines. Each vehicle has its own quirks.

The Right Way to Do an Oil Change on This Engine

A proper oil change on the 2018 Highlander 3.5 isn't complicated, but it does require attention to detail. The 2GR-FKS engine has a few quirks that make the process different from older engines.

Step 1: Gather your supplies. You'll need 6.4 quarts of 0W-20 synthetic oil, a new oil filter, a new crush washer for the drain plug, a socket wrench, an oil filter wrench, a drain pan, and a funnel. The correct oil filter part number for the 2018 model is 04152-YZZA6 or an equivalent that meets Toyota's specifications.

Step 2: Warm up the engine. Run it for about 5 minutes. Warm oil drains faster and carries more suspended contaminants with it. But don't let it get hot enough to burn you.

Warm, not scalding.

Step 3: Lift the vehicle safely. Use jack stands and wheel chocks. Never work under a vehicle supported only by a jack. The driver's side front is where you'll access the drain plug and filter.

Step 4: Drain the old oil. Place the drain pan under the oil pan. Use a socket wrench to loosen the drain plug. Remove it by hand once it's loose.

Let the oil drain completely. This takes about 5 to 10 minutes.

Image source: Bing (Web (fair-use with source credit))

Step 5: Replace the oil filter. The filter is on the front of the engine block, accessible from underneath. Use an oil filter wrench to loosen it. Turn it counterclockwise.

Be careful, it's full of oil. Let the residual oil drain into the pan. Before installing the new filter, apply a thin coat of fresh oil to the rubber gasket.

This prevents the gasket from sticking. Tighten the filter by hand, then give it another three-quarters of a turn.

Step 6: Replace the drain plug. Install the new crush washer on the drain plug. Torque it to about 30 ft-lb. Don't overtighten.

Stripping the oil pan threads is a costly mistake.

Step 7: Add new oil. Lower the vehicle. Remove the oil filler cap on top of the engine. Use a funnel to add 6.0 quarts initially.

Put the cap back on. Start the engine and let it run for about 30 seconds. This circulates the oil and fills the new filter.

Turn off the engine. Wait 5 minutes. Check the dipstick.

Add more oil as needed to reach the full mark. You'll likely need the remaining 0.4 quarts.

Step 8: Check for leaks. Look under the vehicle for any drips from the drain plug or oil filter. Wipe the areas clean and check again after a short drive.

For a detailed comparison of oil types across other Toyota models, the Toyota Highlander oil type guide provides a comprehensive look at the entire lineup. The 2025 Camry Hybrid oil type recommendations also follow similar principles for synthetic oil selection.

Common Mistakes That Can Damage Your Engine

Even experienced DIYers make errors on the 2GR-FKS. Here are the most common ones and how to avoid them.

Using the wrong viscosity. The engine is designed for 0W-20. Using 5W-30 might seem harmless, but it can cause sluggish variable valve timing response and reduced fuel economy. Stick with the spec.

Overfilling. This is the most common mistake. Pouring in the full 6.4 quarts without checking the dipstick can lead to overfilling, especially if the old oil didn't drain completely. Always check the level after adding oil.

Forgetting the crush washer. The drain plug uses a crush washer that should be replaced every time. Reusing the old one can cause a slow leak. Over time, that leak can cost you a quart of oil without you noticing.

Overtightening the drain plug. Torque spec is about 30 ft-lb. That's not very tight. If you reef on it with a breaker bar, you can strip the threads in the aluminum oil pan.

That's a repair that requires dropping the pan or replacing it entirely.

Not priming the oil filter. Applying oil to the gasket is important. But some people also fill the filter with oil before installing it. That's not necessary on the 2GR-FKS because the filter is mounted sideways.

It just spills. Just oil the gasket.

Checking the oil on a slope. The dipstick reading is only accurate on level ground. Even a slight incline can give a false reading. Make it a habit to check on flat pavement.

Skipping the filter change. Some people try to stretch a filter change to every other oil change. Don't. The filter is cheap.

The engine is not. Replace it every time.

If you're working on other Toyota vehicles, the 4Runner oil type guide covers a different engine platform with its own specific requirements. The Tacoma oil type guide for the 2024 model year also has unique considerations for the turbocharged engine.

What Happens When You Overfill or Underfill

Both overfilling and underfilling cause real damage. They're not equal in severity, but neither is good.

Overfilling. When there's too much oil in the pan, the crankshaft sits closer to the oil surface. At high RPM, the crankshaft whips the oil into a frothy foam. That foam contains air bubbles.

Air doesn't lubricate. The oil pump picks up that aerated oil and sends it through the engine. Bearings, camshafts, and the timing chain all suffer.

Over time, you can get knocking sounds, reduced oil pressure, and eventual engine failure.

Overfilling also increases pressure inside the crankcase. That can force oil past seals and gaskets. You might see oil leaks from the valve cover gasket or the front crankshaft seal.

Those repairs are expensive.

Underfilling. Low oil level means the oil pump can suck air during hard cornering or acceleration. That's a momentary loss of oil pressure. Even a few seconds of low oil pressure can cause metal-to-metal contact in the bearings.

That's instant wear.

Underfilling also means the oil runs hotter. There's less oil to absorb and carry away heat. Higher oil temperatures accelerate oxidation and breakdown.

The oil loses its protective properties faster.

The sweet spot. The oil level should be between the two marks on the dipstick. Closer to the upper mark is ideal. But never above the upper mark.

The difference between the low and high marks is about one quart. That's a safety margin built into the engine design.

For the 2018 Highlander, 6.4 quarts with a filter change puts you right at the full mark. But always verify with the dipstick. No two engines drain identically.

Residual oil varies.

The same principle applies across Toyota's lineup. The Corolla oil type guide for 2025 has similar warnings about the importance of correct oil level. The 2025 Tacoma oil type explained guide also emphasizes checking the dipstick after filling.

Resetting the Oil Maintenance Light After Your Change

After you finish the oil change, the dashboard will still show a maintenance reminder. You need to reset it manually. This is a simple process on the 2018 Highlander.

Step 1: Turn the ignition to the ON position. Don't start the engine. The dashboard lights should be active.

Step 2: Locate the trip meter reset button. It's on the instrument cluster, near the speedometer. It's a small black knob or button.

Step 3: Press and hold the trip meter reset button. While holding it, turn the ignition to the OFF position. Keep holding the button.

Step 4: Turn the ignition back to the ON position. Continue holding the button. The maintenance light will start flashing.

Keep holding until the light stops flashing and turns off. This usually takes about 5 to 10 seconds.

Step 5: Release the button. Turn the ignition off. Then start the engine.

The maintenance light should be off. If it's not, repeat the process.

Some Highlanders have a different procedure depending on the trim level and display type. If the button method doesn't work, check the owner's manual for the specific reset procedure for your vehicle. The manual covers all variations.

This reset is important. It tells the vehicle's computer that the oil has been changed. The maintenance reminder system tracks mileage and time since the last reset.

If you don't reset it, the light will keep coming on at the wrong intervals.

The same reset principle applies to the RAV4 oil type guide for 2024, which also covers the maintenance light reset procedure for that model. The 2025 Camry oil type guide also includes reset instructions for the newer generation.

When to Use Synthetic vs. Conventional Oil

For the 2018 Highlander 3.5, this isn't really a debate. Toyota recommends 0W-20 synthetic oil. Conventional oil doesn't come in 0W-20 viscosity.

It's not available. So the choice is synthetic.

But let's talk about why that matters, because it applies to other vehicles too.

Synthetic oil advantages. Synthetic oil is chemically engineered. It has a more uniform molecular structure than conventional oil. That means it flows better at low temperatures and resists breakdown at high temperatures.

The 2GR-FKS engine runs hot. The dual-injection system and high compression ratio create heat. Synthetic oil handles that heat without breaking down as quickly.

Synthetic oil change intervals. Toyota recommends 10,000-mile oil change intervals for the 2018 Highlander under normal driving conditions. That's with synthetic oil. Conventional oil would need to be changed every 3,000 to 5,000 miles.

The longer interval saves you time and money, even though synthetic oil costs more per quart.

Can you use conventional oil in a pinch? If you're stranded and the only oil available is 5W-30 conventional, you can use it to get home. But change it out as soon as possible. The engine won't fail immediately, but running conventional oil for a full interval is not recommended.

The variable valve timing system and timing chain are designed around the flow characteristics of 0W-20 synthetic.

High-mileage synthetic oil. For engines over 75,000 miles, high-mileage synthetic oil is a good choice. It contains seal conditioners that help keep gaskets pliable. This can reduce oil consumption and leaks.

Just make sure it's still 0W-20 and meets the API SN/ILSAC GF-5 standards.

Cost comparison. Synthetic oil costs about 25 to 30 percent more than conventional oil. But over 10,000 miles, the cost per mile is actually lower because you change it less often. For the 2018 Highlander, the math works in favor of synthetic.

For a broader look at synthetic versus conventional oil in Toyota vehicles, the RAV4 oil type synthetic vs conventional guide provides a detailed comparison. The Toyota Sienna oil type guide also covers the synthetic oil recommendations for the minivan lineup.

How Often Should You Change the Oil?

Toyota says every 10,000 miles or 12 months. That's under normal driving conditions. But many owners prefer a 7,500-mile interval for extra peace of mind.

If you do mostly short trips, heavy towing, or extreme temperatures, knock that down to 5,000 miles. The maintenance reminder in your dashboard will guide you. Trust it over a generic sticker.

The key is consistency. Regular oil changes are cheaper than engine repairs.

Tools and Parts You'll Need for a DIY Oil Change

Here's your complete list:

Signs Your Highlander Needs an Oil Change Sooner

Check the dipstick color and level. Dark, gritty oil is a clear warning. Also watch for the check engine light, which can indicate oil-related issues.

Listen for unusual engine noise. If you hear a ticking or knocking at startup, low oil level or thick oil could be the cause. A burning oil smell inside the cabin means a leak somewhere.

The maintenance light is the most reliable indicator. When it appears, change the oil within 500 miles.

Safety Tips for Lifting and Working Under the Vehicle

Never trust a floor jack alone. Always use jack stands rated for the vehicle weight. The Highlander weighs about 4,200 pounds.

Use wheel chocks on the rear wheels and engage the parking brake.

Wear safety glasses and gloves. Hot oil can splash. Let the engine cool for a few minutes after warming it up so the oil isn't scalding.

If you're not comfortable working under a lifted vehicle, pay a professional. It's worth the cost.

Disposing of Used Oil the Right Way

Never pour used oil down a drain, into the ground, or into a storm drain. It's illegal and environmentally toxic. One quart of oil can contaminate a million gallons of water.

Most auto parts stores collect used oil for free. Call ahead to confirm. The used filter also needs proper disposal.

Drain it overnight, then recycle it with the oil or put it in the trash where local rules allow.

Check your city or county for hazardous waste drop-off sites. The EPA offers clear guidelines on used oil management for homeowners.

Frequently Asked Questions About 2018 Highlander Oil Capacity

How many quarts of oil does a 2018 Highlander 3.5 take?

Exactly 6.4 quarts with a new filter. Without a filter change, it's 6.0 quarts. Always check the dipstick after filling to confirm the level.

What oil does a 2018 Highlander 3.5 take?

0W-20 full synthetic oil meeting API SN and ILSAC GF-5 standards. Don't use a heavier viscosity unless it's an emergency. Switch back at the next change.

Can I use 5W-30 in a 2018 Highlander?

In a pinch, yes. But it's not recommended. The engine's variable valve timing system depends on the flow characteristics of 0W-20.

Change it out quickly if you do.

How often should I change the oil in my 2018 Highlander?

Toyota recommends 10,000 miles or 12 months under normal driving. Severe conditions like heavy towing or extreme heat may require shorter intervals. Check the maintenance reminder for guidance.

Final Takeaway: One Simple Number That Keeps Your Engine Running

The 2018 Highlander 3.5 needs 6.4 quarts of 0W-20 synthetic oil. That's the whole game. Get the amount right, use the right oil, and check the dipstick.

Do that, and the 2GR-FKS will run reliably for years.