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Types Of Gas A Mazda 6 Takes (Explained)

Types Of Gas A Mazda 6 Takes (Explained)

In 2002 Mazda launched their competitor to Toyota Camry, Honda Accord, and Nissan Altima with the Mazda 6. Since its introduction, Mazda 6 has gained popularity and now stands among the most competitive products in the mid-size sedan segment. A key element to its success is practicality and owner-friendliness. We are here to dig into the gas aspects of the Mazda 6. Let’s take a look at the car itself and its variants.

All generations of the Mazda 6 take regular unleaded gasoline with an octane of 87. The only exception to this is the 2.3L engine offered in the first generation which takes premium unleaded gasoline with an octane of 91.

Now, it’s time to go into all the details regarding the specific types of fuels that should and shouldn’t be used. Let’s now look at the fuel requirements for every generation as per Mazda.

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Also read: 6 Common Problems Of A Mazda 6

Infographic explaining the fuel for a Mazda 6

Fuel Requirements Based On Engine Type

2013 – Present

2013 is when Mazda introduced the third generation of Mazda 6. It occurred when Mazda had already gained popularity among the mid-size sedan buyers through the Mazda 6. The YouTube reviews about the Mazda 6’s design and practicality pay due to gratitude to the Mazda 6.

The current generation is offered with only one 2.5-liter engine size. The base variants come with a standard version of the 2.5-liter 4-cylinder engine. At the same time, the premium variants add turbocharging to the mix. The base variant delivers 194 HP, while the turbocharged version delivers 227 HP.

In the owner’s manual for Mazda 6, Mazda suggests using fuels with a minimum octane rating of 87. It is standard for both engines. However, we would add that going up the octane rating ladder will undoubtedly add more performance to your engine while increasing its health and life.

EngineFuel Requirement 
2.5-liter 4-cylinder Gasoline87-grade octane minimum
2.5-liter 4-cylinder Turbocharged Gasoline87-grade octane minimum

Also read: How Many Miles Can A Mazda 6 Last? (Answered)


For the second generation, introduced in 2007, Mazda offered two gasoline engines for the Mazda 6. The base version was a 2.5-liter 4-cylinder engine, and the premium variants of the Mazda 6 have a 3.7-liter 6-cylinder engine. Both engines could run on fuels with a minimum octane rating of 87 as per Mazda 6 owner’s manual.

Once again, we would urge car owners to go for higher octane grades when refueling due to its benefits in engine performance and life.

EngineFuel Requirement 
2.5-liter 4-cylinder Gasoline87-grade octane minimum
3.7-liter 6-cylinder Gasoline87-grade octane minimum

Also read: Mazda 6 Transmissions: Overview, Problems, Fluids


The first generation of Mazda 6 was launched in 2002. Considering that Mazda 6 has been around for two decades spanning over three generations in itself, is a statement about Mazda 6’s popularity among buyers. Although the mid-size sedan segment is crowded, it still hangs on to its market share.

The first generation of Mazda 6 came with three engine variants. One of them was a 2.3-liter 4-cylinder engine that produced 166 horsepower, and then there was the higher output 3.0-liter 6-cylinder delivering 220 horsepower. And finally, there was a 2.3-liter 4-cylinder turbo variant as well.

For the 2.3-liter turbo engine, Mazda suggests fuels with a minimum octane rating of 91. We think this should be the standard all across. But for the other two engines, Mazda feels that an 87 octane rating is sufficient. However, we recommend going higher up the octane rating charts to get better output and engine life.

EngineFuel Requirement 
2.3-liter 4-cylinder Gasoline87-grade octane minimum
2.3-liter 4-cylinder Gasoline Turbo91-grade octane minimum
3.0-liter 6-cylinder Gasoline87-grade octane minimum

What Types Of Gasoline Can And Can’t Be Used?

We find it necessary to take a look at what other types of fuel are available in the market today and see if they suit the Mazda 6 or not. Let us move forward and check that.

Reformulated Gasoline

Over the last few decades, the emphasis on the environment and its protection has increased substantially. It is not just verbal, but some legislation has also been implemented to assist the cause. Out of this effort, engineers have come up with friendlier fuel types for us and our atmosphere.

One such fuel type is reformulated gasoline, popularly known as RFG. It is modularized to burn greener and cleaner compared to other types of gasoline available today. It is essential to see what Mazda says about the use of RFG for its vehicles.

We haven’t seen any statements pertinent to RFG in the owner’s manuals for Mazda 6. It compels us to believe that Mazda disapproves of using RFG in its cars. Although the environmental benefits are pretty convincing for RFG, we would still urge the Mazda 6 owners to stay in line with what Mazda recommends. 

However, most manufacturers are okay with their customers using RFG in their vehicles. 

Gasoline/Oxygenated Blends Or E-85

In recent decades, we have seen an increase in ethanol-blended fuels. Primarily this is so because ethanol acts as a performance enhancer for your car. Ethanol-based fuels are mostly used in higher output engines, and there is some precaution to be observed before using them.

The “85” in E-85 represents 85% ethanol blended with only 15% regular gasoline. For such a high concentration, your car’s engine must be compatible, which can be checked by a “Flexfuel” badge or E-85 marking on your vehicle’s fuel cap. If you don’t see these markings around your car, then the vehicle is not E-85 compatible.

Mazda cautions that using ethanol-based fuel with such high concentrations should be avoided. As per Mazda, the maximum blend one may use for the Mazda 6 should not exceed 10% of ethanol blend with 90% regular gasoline.

In our observation, there are a few compulsory precautions for using ethanol-blended fuels. These are:

  • At least 11 liters of fuel should be filled at the time of refueling
  • Keep the vehicle running for a minimum of 7 miles after refueling

Taking the above precautions is important, but they also pose some symptoms linked with E-85. These are:

  • Rough idling and hard starting
  • Building up of residue and corrosion inside the engine

It is always a good idea to stick to the manufacturer’s recommendations concerning the use of ethanol-blended fuels—10% in Mazda 6’s case.

Gasoline With Added Materials

Today, we have many products available that can be used as additives to the gasoline used in cars. Some of these are cleaning agents, some assist with emissions, etc. There are also detergent additives available today that can be used in cars to clean up the engines.

However, with all of the options available today, Mazda still goes against the use of such additives this includes other models like the Mazda 3 and not just Mazda 6. They caution car owners that these additives might interfere with the engine’s performance and may also cause issues for the emissions control systems of your car.

Gasoline With MMT

MMT is added to gasoline as an octane enhancer. It was initially sold as a supplement, but nowadays, it is used for its octane enhancing characteristics. Mazda doesn’t say anything concerning using MMT blended with regular gasoline. A good idea is to not use MMT since the likelihood of voiding your car’s warranty is relatively high.

What If I Hear A Knocking Noise From The Engine After Refilling?

Since Mazda suggests 87 as the minimum octane grade for fuel to be used, there are chances when such low octane grade fuel can cause engine knocking, which can be easily fixed by using fuels with higher octane grades such as 91 or above. If it doesn’t fix the issue, it is time to take your car for a thorough check-up.

Please keep in mind that a slight knocking noise is normal in conditions of high performance such as driving uphill or towing.

Also read: Mazda 6 Towing Capacity: Can It Tow a Camper Trailer, Boat, or Jet Ski?

Does the Mazda 6 Have Good Gas Mileage?

2013 – Present

The current generation of the Mazda 6 has a 2.5-liter 4-cylinder non-turbo engine and one with a turbocharger. Both engines crank out a decent amount of power, but the lower output variant is the one that wins the battle of fuel economy.

The standard 2.5-liter 4-cylinder non-turbo engine does at a minimum of 24 miles per gallon while reaching a respectable number of 39 miles per gallon. It is among the best in its class. However, the turbocharged 2.5-liter 4-cylinder does 23 miles per gallon on a bad day with 31 miles per gallon at its best.

EngineLowest Combined MPGHighest Combined MPG
2.5-liter 4-cylinder Gasoline2439
2.5-liter 4-cylinder Turbocharged Gasoline2331


For the second generation of Mazda 6, a base variant 2.5-liter 4-cylinder was offered in addition to a higher output 3.7-liter 6-cylinder engine. Both of these were on sale in North America from 2007 to 2013. 

The 2.5-liter engine could achieve a maximum of 30 miles per gallon, while it could only do 20 miles per gallon on its worst day. The 3.7-liter variant, on the other hand, could reach a maximum of 27 miles per gallon, while its lowest being 17 miles per gallon. It clearly shows that the 2.5-liter variant was more fuel-efficient.

EngineLowest Combined MPGHighest Combined MPG
2.5-liter 4-cylinder Gasoline2030
3.7-liter 6-cylinder Gasoline1727


The first generation of Mazda 6 was available from 2002 till 2007 when the second generation was launched. The first generation of Mazda 6 was offered with a 2.3-liter 4-cylinder engine as a base version. A turbocharged version of the same engine was also available in addition to a 3.0-liter 6-cylinder engine for the high output aficionados. 

The non-turbo engines could be run using fuels with a minimum octane rating of 87, while 91 was the minimum suggested octane rating for the turbo version.

The 2.3-liter non-turbo could achieve a maximum of 29 miles per gallon while achieving a minimum of 20 miles per gallon. The turbo engine could do 17 miles per gallon but could also reach 23 miles per gallon. For the 3.0-liter engine, the best fuel economy number was 25 miles per gallon, and the worst was 17 miles per gallon.

EngineLowest Combined MPGHighest Combined MPG
2.3-liter 4-cylinder Gasoline2029
2.3-liter 4-cylinder Turbo1723
3.0-liter 6-cylinder Gasoline1725

What’s The Gas Tank Size Of Mazda 6?

Since electric cars have emerged, the term “Range Anxiety” has popped up. It refers to anxiety caused by battery depletion and adds to the driving stresses. Drivers faced a similar issue if the fuel tanks had less fuel capacity.

We are happy to report that Mazda 6 decreases this stress significantly by installing a decent-sized fuel tank in the Mazda 6. The first generation of the Mazda 6 had a 14.5 gallons fuel tank. The 2nd generation had a fuel tank with 18.5 gallons capacity, and the current generation had a fuel tank with 16.4 gallons of fuel capacity.

With these fuel tank capacities, car owners can easily achieve a distance of 250 miles on a single fill-up.

EngineGas Tank
3rd generation Mazda 616.4 Gal
2nd generation Mazda 618.5 Gal
1st generation Mazda 614.5 Gal

How Much Does It Cost To Fill Up A Mazda 6?

With the high fuel prices today, knowing how much it will cost a car owner to fill up their gas tank is essential. The current generation of Mazda 6 will cost you at least $62.89 and at most $95.45 for a full tank. 

The 2nd gen of Mazda 6 will be at least $70.94 and $107.67 at most. The first generation of Mazda 6 will cost $55.61 at least and at most $84.39 for a full tank.

GenerationFuel tank size (Gallons)Cost (Cheapest)Cost (Most Expensive)
3rd Generation16.4 Gal$62.89$95.45
2nd Generation 18.5 Gal$70.94$107.67
1st Generation14.5 Gal$55.61$84.39


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