What is the Best Gas for a Dirt Bike?

To ensure the best performance and longevity of the dirt bike, you’ll need to use suitable gas according to the bike’s specifications.

Dirt bikes have either a 2-stroke or a 4-stroke engine. Fuel with an octane rating anywhere between 87-93 works alright for these bikes. 

This article is going to cover the types of gas for dirt bikes, the best gas for 2-stroke and 4-stroke dirt bikes, and how to know what gas to use.

Types of Gas for Dirt Bikes 

There are three types of dirt bike gasses available at gas stations. These are divided on the basis of octane ratings from the lowest to the highest.

1- Regular / Unleaded Gas

Unleaded gas simply means gas without lead compounds. Regular unleaded gas (RUG) is a by-product of crude oil, generally containing 85–87 octane ratings, 10% ethanol, and no tetraethyl lead additives.

It’s the most commonly used gasoline as it’s not expensive. It burns faster and is suitable for low-compression engines.

2- Premium Gas

Premium gas contains higher octane ratings of 91-95, which reduces the engine knocking constraints, and consumes less energy. This gas contains detergent additives with the least polluting characteristics.

A higher octane number doesn’t automatically increase the engine’s efficiency. Some engines might need premium fuel for better performance otherwise it’s not necessary to use the premium fuel.

3- Race Fuel:

Race fuels imply a high octane rating of gasoline. Which is between 100 to 120, this improves performance as they are used for engines with higher compression rates. 

This contains more additives such as ethanol, methanol, or lead. Also, it combusts quickly, preventing carbon and deposits from ending up in the engine.

What is Octane?  

Octane number is the measure of the anti-knocking property and stability of a fuel. It represents how good the fuel is at resisting pre-ignition or detonation in an internal combustion engine.

High-performing vehicles have a precise ignition time and often a higher compression rate. For such vehicles, fuel with a higher octane number is recommended. Otherwise,  regular unleaded fuel performs really well.<Source>

What is Ethanol?

Ethanol, also known as grain alcohol, is a renewable fuel, composed of ethyl alcohol (the same as used in beverages), and is made from various plant materials (biomass). Gasoline consists of 10% ethanol and 90% gasoline to reduce air pollution.

For its production starch from plants is fermented and distilled into sugars and these microbes are turned into ethanol. <Source>

  • 85 Octane

The fuels with 85 octanes are specifically intended for high-elevation areas, where the barometric pressure is lower which results in a lower temperature for compression.

This fuel contains higher ratings of octane as they are designed for engines with higher compression ratios to resist knocking and detonation.

  • 87 Octane Gasoline

87 octane is commonly referred to as “regular gasoline” in most states. This is used for engines with higher compression ratios.

The higher the gasoline rating the lower knocking or detonation it’ll produce.

  • 90+ Octane Gasoline

Fuels with a 90+ octane rating are often termed “Premium gas”. Octane-rating fuels of 91 or 93 are used in higher-performing engines as it’s highly stable and resists knocking or spontaneous combustion.

Higher octane fuels have higher concentrations of additives and detergents which can help in keeping the engine clean. This can provide better performance to the engines designed specifically for higher octane fuels.

  • 110 Octane

110 Octane, often known as “Lead racing fuel”  is an ethanol-free gas, which works well for engines with compression ratios up to 13:1. 

If you’ve got an engine with a compression rate lower than 12:1 then this fuel won’t perform well as your bike will go slower. <Source>.

  • E85

E85 also known as fuel flex is a term used for higher levels of ethanol-gasoline blends containing 51-83% ethanol. The combustion of this fuel is fine as it contains higher oxygen content.

E85 and other ethanol-gasoline blends are adjusted seasonally and geographically to ensure that the vehicle starts properly, operates well, and guarantees safety in varying temperature conditions. <Source>

What Kind of Fuel Does a 4-Stroke Dirt Bike Take? 

For better performance, 4-stroke engines use regular unleaded gasoline or premium gas with an octane rating of at least 89- 91. One of the recommended unleaded fuels is VP MR12, which can generate maximum power in 4-stroke bikes.

Unlike 2-stroke, fuels with ethanol content can work well for the 4-stroke dirt bike. 

Do You Have to Mix Gas and Oil for a 4-Stroke Dirt Bike? 

No, 4-stroke dirt bikes do not require the mixing of gasoline and oil as these bikes have separate oil reservoirs. The oil can lead to clogging the spark plug resulting in a decline in performance.

What’s the Best Gas to Run in a 2-Stroke Dirt Bike? 

For a 2-stroke motocross engine, go for higher octane unleaded gas of rating between 92 and 93-octane as lower octane numbers tend to detonate in these engines.

It’s recommended to use fuels with the least or no ethanol content, also race fuel such as VP 2 stroke premixed race fuels, this work well for 2 strokes and can also provide better performance.

Do You Have to Mix Gas and Oil for a 2-Stroke Motorbike? 

Yes, 2-stroke dirt runs with a mixture of gas and oil, unlike 4-stroke engines. Without the oil mixed in the fuel, it’ll not have enough lubrication needed to function properly which can lead to damage.

A 2-stroke engine requires mixing of gasoline with oil, you can check STA-BIL 2-cycle oil with fuel stabilizer. The ratio depends upon the manufacturer’s recommendations, which you can check out in the owner’s manual.

Advantages of Gas Dirt Bikes 

Gas dirt bikes generally have more power as they can endure rough off-road tracks, and higher jumps over hills and rocks, also they can be ridden on super sandy trails.

These bikes are less costly as compared to electric bikes. Gas dirt bikes can be ridden on longer ranges as they can be refueled quickly.

These bikes are capable of generating more horsepower and perform better and faster than electric ones.

Disadvantages of Gas Dirt Bikes

One of the cons of riding a gas dirt bike is the noise it creates which can be unpleasant to cope with. Also, the emission of carbon dioxide contributes to air pollution which can be harmful to the environment.

Gas dirt bikes are less costly to purchase however they require consistent maintenance and upgrading to function properly including oil changing and fueling as well.  <Source>

How to Know What Gas to Use? 

The foremost important factor that decides the suitable fuel for your dirt bike is the engine specification. A dirt bike can either have a 2-stroke or 4-stroke engine.

Engines with higher compression ratios use a gasoline of suitable higher octane in order to prevent detonation, as lower octanes can destroy the internal combustion engine.

Prefer using the fuel recommended by the manufacturer that you can find printed near the tank or on the owner’s manual.

Best Pump Gas for Dirt Bikes?

Depending on the type of motocross bike, the fuel type between 87-octane and 92-octane will work well. 

Some dirt bikes may require premium fuel of higher octane of at least 91 rating for optimum performance.

How To Properly Store Gas For Dirt Bikes?

While preparing for long routes, you’ll need to carry extra fuel. Which needs to be handled carefully or can lead to consequences. Make sure that you keep the fuel at room temperature. 

You’ll need to store extra gasoline containers tightly closed. You can use Gas Can for Dirt Bikes as it’s a highly flammable liquid. 

Effects Of Using Wrong Gas In Dirt Bike?

If you’ve filled the bike’s tank with the wrong octane grade, It can result in damage to the internal combustion and a knocking sound from the engine. Using the wrong type of gas can lead to a decline in performance.


Usually, three types of fuels are available at the gas station based on the octane rating. This includes regular unleaded gas, premium gas, or race fuels. 

Dirt bikes use fuel of octane rating anywhere between 87-93 or higher, the higher the octane rating will be the better will be the performance of the engine. Use the fuel that is recommended in the user’s manual for best performance.


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