Best Oil For RX8

Find the best oil for rx8

A Mazda RX-8 is a really cool car to own, but then there is a high probability that you might be pretty cranky around the time for an oil change. There are always discussions happening on the best oils for this car and no one has ever come to a unanimous agreement. If you are someone who loves your car to death but is pretty much lazy to go through all the troubles to choose the perfect oil for your engine, we are here to help you out.

For anyone who needs a little background, the Mazda RX-8 is a sports car manufactured by the Japanese automobile manufacturer Mazda between 2002 and 2012. It is powered by a rotary Wankel engine, like its predecessors in the RX range.

Oil Type for Mazda RX-8

The Mazda Motor Corporation recommends a non-synthetic oil for the Mazda RX-8 rotary engine with an oil viscosity of 5w-20 for North America and 5w-30 for others. Mineral oil is considered to be the safest for RX-8 which has a rotary engine, as it is refined from crude oil which results in minimal carbon deposits. However, tests have proved the higher efficiency of synthetic oils in protecting your car engine compared to mineral oils. Therefore, it is advisable to use either synthetic or non-synthetic oils according to your preference.

Best oils for Mazda RX-8

 ProductOil TypeViscositySizeCheck Today’s Price
1.Idemitsu Fully Synthetic Petrol and Diesel Engine OilSynthetic5W-303.5 LClick Here
2.AMSOIL 5W-30 XL Fully Synthetic Motor Oil for CarsSynthetic5W-303.78 LClick Here
3.Pennzoil 550045217 5 quart 10W-40 High Mileage Motor Oil (SN Jug)Conventional10W-405 QuartClick Here
4.Castrol 03057 GTX Magnatec 5W-30 Motor Oil – 5 QuartSynthetic5W-305 QuartClick Here
5.AMSOIL BOOSTED XL 5W-20 Synthetic Motor OilSynthetic5W-201 GallonClick Here

1. Idemitsu Fully Synthetic Petrol and Diesel Engine Oil

best oil for rx8

Idemitsu is a leading brand in high-quality synthetic oils that are engineered for maximum performance and exceeds the API and ILSAC standards. The oil is exclusively designed using “Idemitsu Advanced Additive Technology (IAAT)” for the latest generation fuel-efficient petrol & diesel engines and is made for providing outstanding engine performance, torque and horsepower.

This fully synthetic oil ensures excellent start-up performance at low temperatures. This oil which is equally durable at high temperatures is a higher fuel economy oil. The cleanliness of the engine is efficiently maintained as effectively minimizes the formation of sludge in the engine parts. 


  • It is a higher fuel economy oil.
  •  The oil offers outstanding start-up performance in low temperature
  •  It ensures great durability at high temperatures.
  •  The oil provides more stringent sludge control for the engine parts, thus effectively keeping your engine clean for engine longevity.
  •  It delivers supreme protection against engine wear & corrosion.


  • This oil is not easily accessible in all locations.


This is one of the best oils out there with 5W-30 viscosity. The engine runs very smoothly compared to other oil brands. You can easily push to high RPMs without hesitation. The brand is highly recommended by experts for your Mazda RX-8 engine.

2. Amsoil XL Fully Synthetic Motor Oil for Cars

This brand of oil has been there in the market since 1972 and there is that perfection in their products that comes only through experience. The product is the best choice for those who prefer exceptional protection for their vehicle. Excessive oil consumption, engine wear, and tear, and corrosion, which are the major issues that any engine faces. The Amsoil XL fully synthetic oil is engineered with a boosted formulation which ensures maximum performance and intense lubrication. They consistently outperform various synthetic and non-synthetic oil brands out there.


  •  This oil provides extra cleaning power.
  •  It offers supreme wear control.
  •   Efficient protection across different ranges of temperatures is ensured. 
  •   The oil offers an excellent fuel economy.
  • It is the extra engine protection that allows up to 12,000 miles between oil changes.
  • The oil drain intervals are extended. 


  • There is dissatisfaction that it doesn’t perform up to the promised results.  


 The oil is perfect for your car as it runs smoothly with improved mileage.  It is an opted choice as it features functionalities that tremendously boost the engine response. The adaptability across temperatures is also a notable feature. 

3. Pennzoil High Mileage Motor Oil

 The oil is a highly popular product for many decades because of its versatility. It is well-suited for a wide range of vehicles out there, mostly the old ones.  Pennzoil brand is extremely popular for its affordability and accessibility. The oil is reusable which makes it even more economical and budget-friendly.


  •  Conventional motor oil compatible with most vehicles out there and especially for  RX-8 which recommends the use of non-synthetic oils.
  • It efficiently prevents sludge and other damaging engine deposits.
  •  It cleans up engines by gently lifting sludge deposits off engine surfaces and dissolving them safely in the oil.
  • The engine is kept clean and responsive.
  • The lubrication is improved.
  • When compared to other conventional oils, this improves the gas mileage.
  • It improves fuel economy.
  • It comes inefficientin efficient packaging that prevents leaks. 


  • Being a conventional oil, it has lesser efficiency compared to the new fully synthetic oils available out there.


This conventional oil is a budget-friendly choice. The oil works perfectly in older cars and Mazda is one of them recommending the use of non-synthetic oils, the product is a great choice.

4. Castrol GTX Magnatec Motor Oil

Castrol is the most trusted brand for many decades and you can never go wrong with your choice. The Castrol GTX Magnatec Motor Oil is specifically designed to navigate your car through severe driving conditions. This premium oil comes with a multitude of features that enhances the efficiency of the engine. 

The oil film strength is increased which improves the lubrication and reduces the metal-to-metal contact. This ensures that the engine wear and tear is minimized which will improve the engine life. 

This fully synthetic oil can work against viscosity breakdown. The oil thickening that is common at high temperatures is thereby avoided. 

This oil works six times better against the common sludge formation. 


  • The oil reduces engine wear.
  • It leaves the critical engine parts 4 times smoother.
  • It adds a layer of protection during warm-up and beyond.
  • The oil clings to critical engine parts when the oil drains down.
  • It resists sludge formation.
  • The oil works against viscosity breakdown. 
  • It prevents oil thickening at high temperatures. 


  •  Some consumers claim it to be over-priced


The oil is worth every penny as the brand never fails to keep its promises. The enhanced wear protection, and the improved oil viscosity break down improves both the performance of the engine and the vehicle. 

5. AMSOIL BOOSTED XL 5W-20 Synthetic Motor Oil

As mentioned above, Amsoil is the best choice for your Mazda RX-8 as testified by many of its users. A leading brand that never compromises with the quality of their product, they provide you with the finest motor oils which will definitely enhance the functioning of your engine. Amsoil Boosted XL Synthetic Motor Oil meets the required specifications of your RX-8. The extraordinary wear protection and the extended oil change intervals make it an economical choice. 


  •  It delivers flawless protection against engine wear and tear.
  •  The additives in the oil keep your engine clean and vigorous.
  • The oil maintains fluidity even at lower temperatures.
  • The oil change intervals can be extended up to 25000 miles.


  • This oil is costlier than conventional oils.


The oils from Amsoil are perfect for customers who need oils that deliver the the best performance with maximum protection and reliability. It also offers better mileage compared to its counterparts.


What is the oil capacity of the Mazda RX-8 engine?

The total oil capacity of the RX-8 is around 7.5 liters although only 4.5 liters of this is in the sump. The remaining oil is split up laying in the coolers, cooler lines, and the engine. This means that during a single oil change, we are only able to replace around 4.5 liters of oil, which makes regular oil changes compulsory to ensure the smooth functioning of your car engine.

How often should you change the motor oil in a Mazda RX-8?

It is recommended that the oil and oil filter is changed at every 6000 miles or 6-month intervals.

Which is the best oil filter for the Mazda RX-8 engine?

Stock oil filter is one of the best oil filters available out there. Alternate options are WiX, K&N, Mobil 1, or Royal Purple can be used. 

How to change the oil in a Mazda RX-8 easily?

It is the regular changing of the engine oil that ensures longer life and smoother performance of the vehicle. You will require these basic tools for an oil change. The steps given below can be followed to carry out an oil change in Mazda RX-8.

  •  Any suggested oil 
  • Oil drain pan
  • Sockets of different dimensions
  • Wrench 
  • New oil filter
  • Flathead screwdriver
  • Jack stand 
  • Funnel

Step 1: Jack your vehicle

This provides ample space underneath to work.

Step 2: Run the engine 

This makes sure that there is oil flow. 

Step 3: Open the hood

This is to remove the engine cover. This is followed by locating the oil filler cap. 

Step 4: Remove the breather hose off the oil filler cap

This will ensure faster draining. 

Step 5: Remove the oil drain plug

Place a drain pan under this before removing the plug. Let it drain. 

Step 6: Replace the crush washer on the oil drain plug

After the oil has completely drained replace the oil drain plug with the new washer.

Step 7: Replace the oil filter

The engine oil change is complete with the oil filter replacement, The filter which is behind the dipstick must be removed and replaced. Dab clean oil around the o-ring so that it sits carefully after replacement. 

Step 8: Refill the engine oil

Using a funnel pour the oil into the engine. After the fill, run the oil to operating temperature. 

Step 9: Check the oil level and reset

Use the dipstick to check the oil level. After the correct level is achieved, reset the service indicators. Do not forget to double-check for leakage.  


The debates around the suitable oils for Mazda RX-8 might never cease, however, we are confident that the products that we have suggested here will help you run your car smoother. These will definitely boost the performance and ensure smoother performance. 


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