On this blog, we do a lot of research regarding specific questions about different cars. In fact, we’ve written extensively about Mazda 3 and the various questions you might have about this car, whether that’s specific issues that may come up, or Mazda 3 best year.
Today we’ll look at the Mazda 3 once more and answer what kind of gas this car requires. We’ve gone through the owners’ manuals of the 2007 – present-day Mazda 3 to find the answer.
So, what types of gas does a Mazda 3 need?
Mazda 3, manufactured between 2003 – 2013, take regular, unleaded gasoline with an octane rating of 87, except for the 2.3L turbo engines, which take premium, unleaded gasoline with an octane of 91. Mazda 3, manufactured from 2014 onwards, take regular, unleaded gasoline with an octane rating of 87.
However, that doesn’t tell the whole story. Below we’ll dive into what kind of gas this car takes. We’ll talk about reformulated gasoline, E-85, and gasoline with additives. Should or shouldn’t you use this for the Mazda 3?
We’ll also talk about the fuel mileage of each generation as well as possible knocking noises and so much more. Read on!
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Differences Between Generations Of Mazda 3
As stated previously, most types of Mazda 3 make use of regular, unleaded gasoline with an octane rating of 87, while others make use of premium unleaded gasoline with an octane of 91. However, why’s there a difference?
This is because the one car that had 91 octane recommended between 2003 – 2013 was the 2.3L Mazda 3 with a turbo engine. It’s very common in the car industry to advise premium gasoline (with an octane of 91 or higher) when a car has a sizeable engine or when it’s equipped with a turbo.
This is because these engines can derive better performance from this higher octane gasoline. On the other hand, smaller engines or engines without a turbo aren’t capable of benefiting from higher octane gasoline which is why 87 octane is recommended.
This also answers whether it’s a good idea to use premium gasoline in the Mazda 3 when regular gasoline is recommended: it’s not. You can use it, and it won’t hurt the car, but it will be more expensive without gaining any benefit.
However, doing it the other way around (using 87 octane when 91 is advised) is not advisable, and we’ll discuss that later.

What Types Of Gasoline Can And Can’t Be Used?
Now that we know what kind of gasoline should be used in terms of octane levels, it’s time to dive deeper into the different kinds of gasoline that are available on the market and which ones should and shouldn’t be used with the Mazda 3.
Reformulated Gasoline
One of the first things we need to discuss is the use of reformulated and non-reformulated gasoline. Reformulated gasoline is the gasoline that’s been developed to burn cleaner than non-reformulated gasoline. Therefore, it’s better for the environment than the alternative.
For this reason, reformulated gasoline has become mandatory in some areas of the United States. Therefore, it’s also good to know that the use of reformulated gasoline is encouraged by Mazda and that the Mazda 3 is fully compatible with this kind of gasoline.
Gasoline/Oxygenated Blends Or E-85
Another element of gasoline that we need to talk about is the use of oxygenated blends of gasoline. Oxygenated blends typically contain some form of ethanol or methanol, which are both biofuels.
It’s good to know that all generations of Mazda 3 are compatible with ethanol, although the percentage of ethanol should not exceed 10%. This is good to keep in mind because gasoline with 15% ethanol is widely available in the United States and shouldn’t be used. Furthermore, no generation of Mazda 3 is compatible with methanol.
Using gasoline with a higher percentage of ethanol or any percentage of methanol will result in severe damage to the car’s fuel system.
Gasoline With Added Materials
One final aspect we need to discuss is the use of additives in gasoline. Online and in stores, you’ll find a range of products supposed to be added to your gasoline. Supposedly, these additives can clean the engine more thoroughly or improve the octane level of the gasoline.
However, it’s good to keep in mind that Mazda strictly advises against using additives in gasoline for the Mazda 3. If you use additives, make sure they’re Mazda certified products and that you discussed this with your dealer.
You shouldn’t use additives in your gasoline because these additives can be very harmful to the engine and the fuel system. Many additives contain silicone or micro metals that harm your engine’s internals.
Instead, it’s advised you buy gasoline that already has all the proper additives mixed into it. TOP TIER gasoline retailers sell this gasoline. It’s been scientifically proven that gasoline sold by these retailers helps the engine stay cleaner. Visit toptiergasoline.com to find a retailer in your area.
What If I Hear A Knocking Noise From The Engine After Refilling?
At the beginning of this article, we mentioned that using 87 octane is not sensible when 91 is advised. You’ll most likely severely damage the engine and the fuel system. It may not even have an immediate effect, but it will hurt the engine’s internals over time.
In some cases, it will have an immediate effect. The most notable one will be a loud knocking noise of the engine. This indicates misfiring of the engine because of the lower octane that’s used (which is not compatible with the engine).
Please note that a faint knocking noise is never a problem. This may happen when the car performs near its peak, such as when driving uphill or towing.
However, if the knocking is very audible, you’ll have to stop the car and call your dealer or garage. The car will need to be towed and drained of its fuel, and the fuel filter will need to be replaced for the lower octane gasoline to disappear.
For more insight into engine knocking check this video:
Does the Mazda 3 Have Good Gas Mileage?
Now that we’re on the subject of the gasoline that a Mazda 3 uses, we might as well dig a little deeper. Let’s look at the fuel economy of the different generations of the Mazda 3 to better understand this car’s relationship with its fuel.
2004 – 2009
Engine | Combined | City | Highway |
2.0 | 27 | 24 | 32 |
2.3 | 25 | 22 | 29 |
2010 – 2013
Engine | Combined | City | Highway |
2.0 | 30 | 26 | 37 |
2.3 | 25 | 22 | 29 |
2.5 | 25 | 22 | 28 |
2014 – 2018
Engine | Combined | City | Highway |
2.0 | 33 | 29 | 39 |
2.5 | 30 | 27 | 36 |
2019 – Present
Engine | Combined | City | Highway |
2.5 2WD | 30 | 27 | 36 |
2.5 4WD | 28 | 25 | 33 |
What’s The Gas Tank Size Of A Mazda 3?
Mazda 3 manufactured between 2003 – 2012 all have a gas tank size of 14.5 gallons or 55 liters. The 2013 Mazda 3 has a gas tank size of 14.5 gallons or 55 liters, except for the 2.3L turbo engine, which has a tank size of 15.9 gallons or 60 liters. Mazda 3, manufactured between 2014 – 2018, have a gas tank size of 13.2 gallons or 50 liters.
Mazda 3 manufactured from 2019 onwards have a gas tank size of 13.2 gallons or 50 liters for the FWD versions and 12.7 gallons or 48 liters for the AWD versions.
Closing Thoughts
We’ve delved deep into this piece and one thing is certain, knowing what gas to put in your Mazda 3 tank is crucial.
We tackled reformulated gasoline, E-85, and gasoline with additives, not to mention fuel mileage and those pesky knocking noises. Knowledge is power, right? And taking care of your vehicle is key to keeping it running smoothly.
But before you dash off, don’t miss our in-depth article on “Mazda 3 Transmissions.” And if a wheel change is on the cards, then “The Exact Bolt Pattern Of A Mazda 3” is essential reading.
Take care of that Mazda 3, and it’ll take care of you. Happy driving!
Sources
- https://gimmemanuals.com/owners/2019/06/MAMA04274-Mazda-2004-Mazda3-Owners-Manual.pdf
- https://gimmemanuals.com/owners/2019/06/MAMA08270-Mazda-2008-Mazda3-Owners-Manual.pdf
- https://gimmemanuals.com/owners/2019/06/MAMA09269-Mazda-2009-Mazda3-Owners-Manual.pdf
- https://gimmemanuals.com/owners/2019/06/MAMA13265-Mazda-2013-Mazda3-Owners-Manual.pdf
- https://gimmemanuals.com/owners/2019/06/MAMA14264-Mazda-2014-Mazda3-Owners-Manual.pdf
- https://gimmemanuals.com/owners/2019/06/MAMA18260-Mazda-2018-Mazda3-Owners-Manual.pdf
- https://gimmemanuals.com/owners/2020/11/2020-mazda3-sedan-owners-manual-v2.pdf
- https://www.fueleconomy.gov/
Hi! My name is Stefan; I’m the owner and lead writer at TheDriverAdviser.com.
I’m an active writer on this blog myself, as well as a novice car mechanic. For the really technical stuff, I find writers with experience as a mechanic or who have studied mechanical engineering.
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