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Types Of Gas A Kia Niro Takes (Explained)

Types Of Gas A Kia Niro Takes (Explained)

Writing about Kia is almost a daily practice on this blog. Today we will look at what type of gas is best suited for the Kia Niro. The Niro was launched in 2017 and has been a relative success. However, it’s available in three engine configurations, and therefore it can be confusing what type of gas it needs. Here’s a quick answer:

Kia Niro manufactured from 2017 onwards that have a hybrid or plug-in hybrid engine take regular unleaded gasoline with an octane rating of 87. As the name implies, the all-electric Niro EV does not use gasoline at all.

However, this doesn’t tell us the whole story. The article below will discuss what kind of gasoline is used for what type of engine. Furthermore, we’ll discuss different additives that can and can’t be used, what percentage of ethanol is acceptable, and the gas tank size of the different Niro generations. Read on!

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Infographic explaining the fuel types for  a Kia Niro.

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

Reformulated Gasoline

First, we need to discuss the use of reformulated and non-reformulated gasoline. Reformulated gasoline is the gasoline that is designed to burn cleaner than non-reformulated gasoline. For this reason, it has become widely popular in many regions of the United States. It has even become mandatory in many states to use this kind of fuel.

Therefore, it’s good to know that all engine configurations in the Kia Niro are designed to take both reformulated and non-reformulated gasoline. Consequently, you don’t have to worry about what kind of gasoline you put in your engine (at least not for this criteria).

However, we have to say that Kia recommends using reformulated gasoline whenever possible. Like other carmakers, Kia realizes that using this type of gasoline is better for the environment. Furthermore, this type of gasoline doesn’t diminish the performance of your engine in any way, shape, or form, and it also carries the same price as non-reformulated gasoline.

Gasoline/Oxygenated Blends Or E-85

Secondly, we need to talk about using oxygenated blends of gasoline in the Kia Niro. Oxygenated blends of gasoline are types of gasoline that have a certain percentage of ethanol or methanol mixed into them. These oxygenates are made from biomass (such as corn) and burn more cleanly than regular gasoline. However, they also lower the MPG.

In the United States, gasoline typically contains 10% or 15% ethanol. These are referred to as E10 or E15. Both the hybrid and the plug-in hybrid version of the Kia Niro can take gasoline with a maximum percentage of 15% ethanol.

This also means that the use of higher percentages of ethanol, typically E30 or E85, are strictly forbidden. Using these types of gasoline will damage the fuel system and is not covered under warranty. Furthermore, the use of gasoline that contains methanol is also forbidden and will also damage the fuel system.

Gasoline With Added Materials

Furthermore, we need to talk about gasoline with added materials. Typically, these additives are advertised as octane boosters or fuel system cleaners. However, these types of additives can do more harm than good, as explained in the 2022 owners manual of the Niro:

Using fuels that contain Silicone (Si), MMT (Manganese, Mn), Ferrocene (Fe), and other metalic additives, may cause vehicle and engine damage or cause misfiring, poor acceleration, engine stalling, catalyst melting, clogging, abnormal corrosion, life cycle reduction, etc. Also, the Malfunction Indicator Lamp (MIL) may illuminate.

Source, page 57

Instead of using additives, Kia recommends using gasoline that already has all the proper additives mixed into it. Typically, this type of gasoline is sold by TOP TIER retailers. It’s highly recommended you use this type of gasoline to keep your engine in optimum condition. Find a TOP TIER retailer in your area at

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

Hearing a slight knocking coming from the engine is an entirely regular occurrence. Especially when the car is performing at peak levels, such as when you’re towing with your Kia Niro, a slight knocking sound can be heard. However, if this knocking sound becomes very audible and happens right after refilling, you may have more significant problems.

First off, in this case, it’s very likely you’re using gasoline with a lower than recommended octane rating. For example, in the Kia Niro, we would be talking about gasoline with an octane rating lower than 87. This will almost always result in an engine knock.

This knocking noise tells you the engine is misfiring because it can’t handle the octane level used. It’s best to stop your car immediately and call your dealer or garage. Your car will need to be drained from its fuel, and the fuel filter will need to be replaced. Continuing to drive will result in severe engine damage.

Also read: 6 Common Problems Of A Kia Niro Hybrid

What’s The Fuel Economy Of The Kia Niro?

As expected from the Kia Niro, all the drivetrains have an excellent fuel economy. The hybrid version of the Niro typically has a combined MPG of 49, whereas it reaches 46 on the highway and 51 in the city.

The PHEV Niro has a combined city/highway use of 105 MPG, assuming a combined use of gasoline and electricity. If the PHEV runs on gasoline only, you can expect an MPG of 46. The EV Niro ends up with a combined MPG of 112, 102 on the highway, and 123 in the city.

What’s The Gas Tank Size Of The Kia Niro?

Kia Niro, with a hybrid drivetrain (also referred to as HEV), have a fuel tank capacity of 11.9 gallons or 45 liters. The plug-in hybrid Kia Niro (PHEV) has a fuel tank capacity of 11.4 gallons or 43 liters.


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