How Much Gas Does a Lawn Mower Use?

Gas is essential to start and keep a lawnmower engine running. It is important to know the amount of gas required by your lawnmower, the type of gas it uses, and how to identify bad fuel and manage the fuel properly. Not all fuel types are suitable for the engine; some cause it to knock and damage it. Knowing your lawn mower’s fuel capacity will help you make informed decisions when purchasing fuel and learning when to refill it. 

The amount of gas a lawnmower uses depends on its size. A push mower has a capacity of 1 to 2 liters and uses up a full tank when operated up to half an acre. Riding mowers have larger fuel demands and bigger engines. Hence the amount of gas required will be more. A medium-sized riding mower requires up to two gallons of gas, that is up to 7 liters. For large riding mowers, the capacity is as much as four gallons, which is about 12 to 14 liters for a full tank. The quantity of lawnmower fuel is typically calculated per acre. 

How Much Gas Is Enough for Different Lawn Mower Types?

Different lawn mower types, especially in terms of sizes, require different amounts of gas to function correctly. There are three types of lawnmowers, namely Push mowers (also known as walk-behind mowers), riding mowers, and commercial (or tractor) mowers. 

Push Mowers 

They are the smallest type used for lighter work and are designed to cover smaller land areas. The fuel consumption is not so much because it uses less energy to run. In general, the fuel capacity of push mowers is about one liter, and a full tank is used up in half an acre. To mow one acre of grass would require just a little over one full tank. 

loud lawn mower

Riding Mowers 

These are mounted on the operator sits in and use pedals to control the turns, braking, and acceleration. They are suitable for larger land areas, rough terrains, and uneven grounds. It provides better acceleration and power. Riding mowers are either small or large. Small riding mowers need less than two gallons for a full tank, which is over six liters of fuel. Medium-sized ones require up to two gallons. The fuel consumed per acre for small riding mowers is about 1 gallon per acre, while medium-sized ones consume up to 1.5 gallons per acre. 

Tractor/ Commercial Mowers  

These types of mowers are much larger and have the highest fuel capacity. They use up more fuel and cover very large areas. Tractor-style mowers have a capacity of up to three gallons, while commercial mowers hold up to six gallons. They can be used for a more extended period to cover vast areas and rough terrains. 

What Is the Best Type of Gas? 

Lawnmowers require quality gas to operate properly. Bad or adulterated gas can damage the engine easily. The standards to consider when choosing the right kind of fuel for your lawn mower are:

  • Octane rating
  • Ethanol level
  • Lead 

Octane Rating  

The recommended minimum octane rating for quality fuel is 87. Anything less than that can lead to engine knocking. Octane rating shows how heat resistant the fuel is to prevent the air-fuel mix in the engine from igniting prematurely. The higher the octane rating, the better the quality. 

Ethanol Level 

The ethanol level in lawn mower fuel must not be over 10%. A higher concentration of ethanol will lead to increased moisture absorption. The ethanol will retain moisture and corrode the fuel lines. This will damage the carburetor and fuel system and weaken the engine’s casing. 


It is advised to use quality unleaded fuel in your lawnmower engine. Lead in fuel causes the octane level to drop over time and can cause sticky valves.

What Happens When You Use Bad Gas? 

Signs that you may be using bad fuel include- the lawn mower not starting at all, stalling, rough idling, smelly fumes, thumping or sputtering noises. To fix this issue, drain the fuel tank of all the bad gas, drain the fuel filter and clean the carburetor. 

Signs Of Stale or Bad Fuel  

You can tell if fuel is bad by looking at the appearance, smelling it, or how long it has been on the shelf. 


When fuel goes bad, it assumes a darker muddier look due to changes in its chemical properties. Sometimes, it can look amber in color, especially at the early stage of turning bad. 


Bad fuel smells different from regular fresh fuel. The smell turns sour and unbearable.

Shelf life 

Shelf life, in this case, is how long the fuel can stay fit for use. Regular fuel has a shelf life of up to four months. The presence of ethanol in fuel can reduce the shelf life, making it go bad quicker. 

How To Save Gas 

There are things you can do to save gas and, as an effect, save your money and your mower’s engine. 

Use Fresh Fuel 

Avoid letting fuel sit for too long in the engine. It is advised to run your lawnmower sometimes when fuel is sitting in it. Also, do not mix old and fresh fuel. If you have to refill, use up the old fuel first or drain it out and replace it with fresh fuel. The standard quality of fuel for your lawnmower is- octane rating of 87 and above, a maximum of 10% ethanol content, zero lead, and no contamination (water, dirt, etc.)

Add Fuel Stabilizer

Stabilizers keep the fuel intact for a longer time. It maintains the fuel quality and reduces the tendency of the gas to evaporate. 

Adjusting The Altitude   

Using the lawnmower at higher altitudes without the proper adjustment would burn more fuel. It is a must to adjust the altitude above 5000 ft. Other factors that affect fuel consumption include speed, terrain, and acceleration. 

Final Thoughts

Investing in good fuel and good maintenance practices saves you money and protects your lawnmower from damage. Knowing how much gas your lawnmower uses will help you plan and easily detect when something is wrong. This article will enlighten you about how your lawnmower works, the best fuel suitable for its engine, among others.

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