Top 7 Best Oil for Mazda rx8 in 2023

Mazda RX-8 has been a popular sports car among all car enthusiasts. The successor of Mazda RX-7 can provide about 238 horsepower of output.

However, your Mazda requires care and maintenance if you want to get that output consistently. That is why you should use the right engine oil for your RX8.

Also you can see our related comparison guide on: Valvoline vs Mobil 1: Which One is the Best?

RX-8’s engine is really thirsty for petrol and can go 19 kilometers a liter. So, the mileage value is pretty low, and thus, you need to make sure that your engine consumes fuel efficiently.

As time goes on, the efficiency will reduce. So, you will need to pour the right motor oil as it will not only improve fuel consumption but also increase the lifetime of the engine.  

Top 7 Best Oil for Mazda rx8 Engine:

These are some of our personal picks for RX-8, and we will provide our honest opinions.

1. Valvoline Full Synthetic High Mileage with MaxLife Technology SAE 5W-20

Valvoline High Mileage with MaxLife Technology 5W-20 Synthetic Blend Motor Oil 1 Quart (Pack of 6)
  • 40% BETTER WEAR PROTECTION than the industry standard with...
  • EXCEPTIONAL TEMPERATURE PROTECTION no matter the weather with...
  • REFRESH AGING SEALS AND PREVENT LEAKS both inside and outside...

Last update on 2023-09-22 / Affiliate links / Images from Amazon Product Advertising API

This is one of the most favorite engine oils among customers. With enhanced anti-wear additives, you don’t have to worry much about automatic engine breakdown.

It creates an anti-wear film around the engine components which will protect them from friction.

It is completely synthetic, so store it easily in hot and cold environments without worrying about the oil burning or freezing. The detergent present in this oil will make sure that you won’t see sludge and deposits in your oil.

This is made in the United States and is certified by American Petroleum Institute. The best part is that its premium seal conditioners will help in treating leaks present in older engines.

The 5QT can comes with an amazing seal that will prevent any leakage when you store it. The pull tab is very easy to open, and the anti-glug tube will ensure a smooth transfer of oil from the container to the engine.

Valvoline has been providing consistent service to its customers for years, and you can expect flawless performance from this engine oil. This truly deserves its first position in our list of the best oil for rx8.


  • Anti-wear technology.
  • Can withstand high temperatures.
  • Provides lots of viscosity options, including 0W.
  • A well-sealed bottle that is easy to operate.
  • Certified by American Petroleum Institute.
  • Suitable for aviation engines.


  • We have found reports from several customers that Amazon is providing faulty products or oil containers without the easy pour cap. Make sure that there are return or replacement options when buying this product.

2. Valvoline Advanced Full Synthetic Oil

Valvoline Advanced Full Synthetic SAE 5W-20 Motor Oil 5 QT
  • ADVANCED PROTECTION AGAINST the four main causes of engine...
  • 40% BETTER WEAR PROTECTION vs. industry standard as tested in the...
  • 25% BETTER DEPOSIT PROTECTION with superior engine cleaning...

Last update on 2023-09-22 / Affiliate links / Images from Amazon Product Advertising API

This oil contains some anti-wear additives that can provide about 50% more protection compared to industry-standard oils.

It can withstand high and low temperatures with fewer chances of freezing or burning and is completely synthetic. It will not only increase your engine efficiency but also cool your engine when operating at higher temperatures.

It is highly pure and has been distilled properly, so no need to worry about purity and sludge build-up.

There are a lot of viscosity options for this oil, and you can get it in cans of 1QT and 5QT.


  • Very light oil.
  • Fully synthetic.
  • Available in 0W viscosity.
  • Gasoline users can also use it.
  • Can withstand hot and cold temperatures.
  • It does not evaporate and can prevent corrosion and friction.
  • Completely recyclable.
  • Certified by manufacturers and loved by customers.


  • Not usable in diesel engines.
  • Not the ideal oil for two-wheelers and aviation engines.
  • The delivery service may not be satisfying.

3. Valvoline High Mileage Full Synthetic Blend 5W-30 Motor Oil with MaxLife Technology

Valvoline High Mileage with MaxLife Technology SAE 5W-30 Synthetic Blend Motor Oil 1 QT
  • MAXLIFE TECHNOLOGY PREVENTS engine breakdown with 40% better wear...
  • REFRESH AGING SEALS AND PREVENT LEAKS with seal conditioners

Last update on 2023-09-22 / Affiliate links / Images from Amazon Product Advertising API

Recommended by RX-8 manufacturers and loved by all, this engine oil deserves the third position on this list.

This is another oil that has MaxLife technology and can prevent engine breakdowns using the anti-wear additives, which form a durable film around the engine.

Store it wherever you want as it can withstand hot and cold temperatures without burning or freezing. The container is designed to store the engine oil for years without any leakage.

The easy pour cap will help you pour the oil into your engine without making a mess. It will also make sure that no liquid comes out when you are storing the container.


  • Completely synthetic.
  • Works great for old engines.
  • Easy-to-use cap.
  • Can prevent leaks and wear in engines.


  • Not suitable for aviation engines.
  • Some users have reported lifter tick problems.

4. Pennzoil Platinum High Mileage Synthetic Oil

Pennzoil Platinum High Mileage Full Synthetic 5W-30 Motor Oil for Vehicles Over 75K Miles (5-Quart, Single-Pack)
  • Full synthetic 5W-30 engine oil made from natural gas, not crude,...
  • Designed for for vehicles with over 75,000 miles
  • Pennzoil Platinum High Mileage 5W-30 keeps pistons up to 45%...
  • No other leading high mileage motor oil provides better...
  • Formulated to deliver less oil burn off than high mileage motor...

Last update on 2023-09-22 / Affiliate links / Images from Amazon Product Advertising API

This is the next best choice after Valvoline and is more nature friendly compared to others. This oil is made of natural gas instead of crude oil. And Pennzoil’s patented gas-to-liquid PurePlus technology makes the most of its resources.

The presence of natural gas will deliver less burn-off compared to its competitors that make high-mileage engine oils out of crude oil.

It is specially designed for engines that have traveled over 75,000 miles and is one of the best synthetic oils for old Mazda RX-8s. This high-mileage oil will keep your pistons about 45% cleaner compared to other industry-standard synthetic engine oils for RX8.

Pennzoil is one of the best oils when it comes to protection from wear, especially the variant with 5W-30 viscosity.

It will also help in protecting your engines from losing their horsepower. Use this, and you can zoom around everywhere with your Mazda RX8, even if it’s old.


  • Made of natural gas.
  • Full synthetic.
  • It contains fewer impurities compared to any other motor oil.
  • Easy to operate container with ergonomic design.
  • Protects the horsepower of engines.


  • Easy pour cap is absent.

5. Castrol GTX Magnatec Motor Oil

Castrol 03057 GTX MAGNATEC 5W-30 Full Synthetic Motor Oil, Green, 5 Quart
  • ATTENTION: Castrol GTX Magnatec will be transitioning to a brand...
  • Dramatically reduce engine wear
  • Leave critical engine parts 4X smoother. As tested in the...
  • Superior wear protection on critical engine parts
  • For best performance, follow the manufacturer's recommendations...

Last update on 2023-09-22 / Affiliate links / Images from Amazon Product Advertising API

Castrol oil is known for its compatibility with several varieties of engines. And this synthetic oil will make sure that the engine of your Mazda RX-8 always remains smooth.

According to IVA wear tests, Castrol can make all the critical engine parts four times smoother compared to its competitors. This will make your engine less noisy.

It meets the specifications for various engines like API SN Plus, Ford WSS-M2C929, and many more, making it highly popular among vehicle owners and mechanics.


  • Affordable.
  • Wide neck container.
  • Prevents engine wear.
  • The oil sticks to critical engine parts even when idle.
  • Wide range compatibility.
  • Leaves a coating of the anti-wear film when the oil is drained out.


  • We have received complaints claiming that it is not fully synthetic.

6. Castrol Edge 5W-30 Full Synthetic Motor Oil

Castrol Edge 5W-30 Advanced Full Synthetic Motor Oil, 5 Quarts
  • 3X stronger against viscosity breakdown than leading full...
  • 10X better high temperature performance, as measured in Sequence...
  • 6X better wear protection
  • 1.4X better sludge protection, as measured in Sequence VH engine...
  • Meets ILSAC GF-6 to prevent low speed pre ignition (LSPI) and...

Last update on 2023-09-22 / Affiliate links / Images from Amazon Product Advertising API

This is another synthetic oil for Mazda rx8 that will protect your engine from wear, even when operating at high speeds.

The oil tends to stick to each engine part so that no two metal parts come in contact with each other. Castrol can also prevent any formation of deposits in your engine.

Since it is completely synthetic and available in 0W viscosity, you can store it in winter, and it won’t freeze. And this oil will work exceptionally well in hotter temperatures.

The best part of this oil that makes it unique compares to its competitors is its fluid titanium technology. Sometimes engine oils cannot operate properly due to the high pressure put by engines.

But that is not the case for Castrol oil, thanks to its titanium enforcement.


  • Advanced wear protection.
  • Titanium technology to withstand temperature and pressure.
  • Can withstand the cold of winter.
  • Compatible with lots of engines.


  • The container is not ergonomic and prone to leaks.
  • Not good for high mileage.
  • No protection for old engines.

7. Castrol GTX Magnatec Full Synthetic Motor Oil

Castrol 03063 GTX MAGNATEC 5W-20 Full Synthetic Motor Oil, Green, 5 Quart
  • ATTENTION: Castrol GTX Magnatec will be transitioning to a brand...
  • Dramatically reduce engine wear and leave critical engine parts...
  • Add a layer of protection during warm-up and beyond
  • Cling to critical engine parts when the oil drains down
  • API SN; ILSAC GF-5; GM dexos1; Meets Ford WSS-M2C930-A; Meets...

Last update on 2023-09-22 / Affiliate links / Images from Amazon Product Advertising API

Another variant of the Castrol Mangnatec motor oil this oil is also known for its ability to reduce engine tear drastically. It works well under pressure and at high speeds, making it a synthetic oil suitable for Mazda rx8.

This oil can make your engine four times smoother and will cling to the parts of the engine even when it is not working. It will drastically reduce the noise during startup.


  • High value for money.
  • Works very well with Bosch filters.
  • Drastically reduces engine tea.


  • Not good for old engines.
  • According to some customers, the oil is not fully synthetic as it becomes thick at lower temperatures.

Best Oil for rx8 Buying Guide

RX-8 Model Overview

Japanese automobile manufacturer Mazda produced the sportscar Mazda RX-8 between 2002 and 2012. It got some structural changes and performance improvements in 2008. It is powered by a rotary Wankel engine. From 2003, this car was available for sale in North America.

Recommended Oil by Manufacturer

Mazda recommends that you use engine oils with 5W-20 and 5W-30 viscosity. That is why all the engine oils that we mentioned have the same viscosity index.

Among them, you need to choose the right oil based on where you live and the climate of that area. According to Mazda, if you live in North America, use 5W-20 engine oils. If you live outside America, use 5W-30 oils.

Fuel Efficiency

The petrol variants of Mazda RX-8 have an ARAI mileage of 19.0 kilometers per liter and a city mileage of 16 kilometers per liter. This fuel efficiency may decrease over time. So, always refill your car with synthetic oil for RX-8 to maintain this fuel efficiency.

Technical Specifications

Mazda RX-8 has a 1308cc petrol engine. It is a four-seater car with a mileage of 19.0 kilometers per liter. The fuel tank can hold 35 liters of petrol and has a Coupe chassis.

The engine has four cylinders with four valves per cylinder. It comes with a power steering type.

There are four engine variants – Renesis 4-port, Renesis 6-Port. Renesis II 4-Port and Renesis II 6-port.

All the cars produced after 2008 have received structural improvements, thus increasing the overall rigidity. The final drive gear ratio was reduced from 4.444 to 4.777, which gave the Mazda RX-8 improved acceleration and performance.

RX8 Oil Change:

You should know how to change engine oil in your RX-8 by yourself so that you can save a lot of money.

Step One: Tilt the car

Prepare to drain the old engine oil from your car by tilting it. The front end of the car should be facing above. Do that using a jack or an inclined driveway. Start the engine and keep it on for five minutes so that the oil heats up and comes out easily.

Step Two: Drain the oil

Open the hood of the car to take out the dipstick. Insert a vacuum pump into the dipstick tube to suck out all the oil.

Final Step: Insert new oil

Add new oil to your engine while keeping an eye on the oil levels. Make sure that you do not add too much oil. You can even use the dipstick to check the oil levels. Once done, screw back the oil cap on the tube.

RX8 Oil Change Interval

According to the manuals provided by Mazda, you need to change engine oils at 12,500 miles intervals or every 12 months.

Some manuals also say to change the oil after 7500 miles. We checked some forums of RX-8 car owners, and most of them change oils after 3000KM or three months.

RX8 Maintenance Schedule (Standard Practice)

As time goes on, you will need to do proper maintenance so that it can increase the lifetime of your car. Here is the recommended maintenance plan for Mazda RX-8.

Every 10,000 miles/12 months:

  • Replace the engine oil and filter.
  • Check the brake lines, cables, brake linings, and rotors.
  • Check the CVT liquid.
  • Check transmission fluids and differential gear oil.

Every 18,000 miles/1.5 years:

  • Replace the microfilter.
  • Check the performance of the battery.

Every 20,000 miles/2 years:

  • Check the EVAP steam pipes and fuel lines.
  • Replace all brake fluids.
  • Check all the suspension parts, steering gears, axles, and linkages.
  • Check the exhaust system.

Every 30,000 miles/3 years:

  • Replace the air filters.

Every 40,0000 miles/4 years:

  • Check drive belt. Replace them if they are damaged.

Every 105,000 miles/7 years:

  • Replace spark plugs. (Replace the plug if the gap exceeds 1.35mm)
  • Replace engine coolant.


1. How much oil does RX8 take?

Mazda RX8 can hold around 7.5 quarts of oil. But only 4.5 quarts are available in the reservoir, while the remaining amount is used by the engine block, coolers, and cooler lines. Thus, you can replace only 4.5 quarts of oil.

2. What is the best way to maximize fuel mileage?

Here are some ways by which you can maximize your fuel mileage

  • Replace engine oil regularly.
  • Make sure to shift gears efficiently.
  • Use cruise control.
  • Go easy on the gas and brake pedals.
  • Shut off your engine if you have to stop for more than a minute.
  • Avoid rush hours, if possible, to avoid unnecessary acceleration and breaking.

3. Does RX8 need synthetic oil?

Mazda recommends their users use non-synthetic oils. However, most users use synthetic oils. As long as you select the oil with the proper viscosity index, you’re good to go.

4. How to choose motor oil for RX8?

You can take a look at the recommendations that we have provided above in this article.  Other than these, look for oils with the same viscosity index. You can also talk to your car dealer to select the best motor oil for rx8.

5. How should I dispose of my used oil?

Here are some things that you can do to dispose of your used engine oil:

  • Send the motor oil to local landfills.
  • Send the oil to your local auto store.
  • Sell the oil to dealers who would send it to refineries.

So, what is the Recommended Oil for RX8?

As you can see from our recommendations, Valvoline Full Synthetic Oil is the best oil for Mazda rx8. It has amazing anti-wear properties and can prevent leakages in old engines.

Since this oil is completely synthetic and is available in 0W viscosity, you can store this oil in the winter without worrying about the oil getting frozen.

Also, the container is completely leakproof, and the anti-glug tube will help in transferring the oil to the reservoir without making much mess.

Despite its share of disadvantages, the number of benefits this oil provides makes it the best synthetic oil for rx8.

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