A lot of people are under the misconception that their lawn mower’s engine will run better if they use premium gas rather than regular. Even for car engines, I’ve heard a lot of people say that their car will run “cleaner” on “higher quality” gas. While premium gas is listed as “required” for some engines, using regular gas is usually always absolutely fine.
You’re probably wondering if it’s better to put regular or premium gas in your lawn mower…
You should use regular gas in your lawn mower. Running a smaller engine on premium gas isn’t necessary. Premium gas is designed for engines with a higher compression ratio which are generally found in high powered cars. While premium gas may not hurt your mower’s engine, it will hurt your wallet.
You won’t benefit from the extra cost of premium gas. As always, make sure you refer to the owner’s manual for guidance on what fuel to use in your mower.
What’s the difference between premium and regular gas?
The title given to a certain type of gas depends on the octane number of the fuel.
In the US, regular gas has an octane level of 87 and premium gas an octane level of 91-93.
This definition can slightly vary by state in the US.
The octane number
The octane number is a measurement of the knock resistance of a fuel. Higher octane fuel can allow the use of higher compression ratios. Without boring you with what happens in a combustion chamber, all you need to know is that higher octane numbers are appropriate for high performance engines that compress the mixture more than a normal engine.
Use a fuel stabilizer!
Adding a fuel stabiliser to your fuel is one of the best ways you can preserve your mower’s engine. STA-BIL (link to Amazon) works in all gasoline and ethanol blended fuels.
The general assumption about premium gas for lawn mowers
The word “premium” tends to imply that something is better. Especially compared to something labeled as “regular”. The general assumption is that a premium is of higher quality and will lead to increased engine lifetime, decreased emissions and better performance.
In reality, you won’t get any of these benefits from using premium fuel in your mower. You certainly won’t get more power from using premium gas!
In the context of fuel, how well a particular type functions depends on the type of engine its being used in. If you tried to run a high-performance engine on too low of an octane fuel, the engine will not as well as it possibly could. Luckily for you, your lawn mower’s engine is not a high-performance engine. An engine that’s designed to run on regular fuel isn’t going to see any benefit from using a higher-octane option.
The overwhelming majority of car engines in the US need regular gas. The only reason to purchase fuel with a higher-octane rating is to prevent knocking on high performance engines.
Premium starting fluid
This premium starting fluid (link to Amazon) from Preston is pretty useful too. It helps start engines with either too little or too much fuel.
Why premium gas costs more than regular gas
Premium gas can be significantly more expensive, but why does it cost so much more?
There’s no standalone reason why premium gas is more expensive than regular gas. Two of the gas companies can simply charge more because there is less competition. It’s also harder to produce.
What type of gas is best for lawn mowers?
I’d recommend using a fuel with an octane rating of 87 octane or higher for all of your mower’s. There’s not really any need to go higher. 89-93 octane fuels are designed for high powered cars and vehicles.
It’s not just about the octane number…
The ethanol concentration is important too. Ethanol can absorb moisture which can cause issues with your carburetor. It’s recommended that your fuel mix contains no more than 10% ethanol or you could face problems when trying to start your lawn mower.
In general, ethanol can be but it’s not something to worry about if you’re using the fuel frequently and it’s not sitting for a long period of time.
I like this ethanol-free fuel (link to Amazon) for 4-cycle engines. It’s pre-blended and can be used in all different types of outdoor power equipment.
How to know what fuel to use in your lawn mower
If the manufacturer doesn’t recommend a certain type of fuel for your mower then you probably shouldn’t be using it. Using an incorrect fuel could potentially cause damage to the components which can be very costly.
I’d recommend referring to the owner’s manual. If you no longer have access to that then you can try googling the serial number to find more information about your mower’s engine requirements.
You have a few options when it comes deciding on which fuel you should use in your lawn mower. Whichever you decide to choose, the gas should be fresh and clean. Ideally, you should add some stabilizer to keep the fuel from degrading which can lead to issues starting the mower and poor performance.
They key takeaway is that there is no benefit if the octane is higher than what the engine requires.
Your mower will run just fine on regular gas. It will not run any better on premium fuel so don’t waste your hard-earned money buying more expensive fuel.
In general, I’d recommend using the lowest octane fuel you can find.
Here are some of my favorite lawn care products
Thanks a lot for making it to the end of this post! I hope you found it useful. Here are some lawn care products that I use and that I think you’ll also find helpful. These are affiliate links, so if you do decide to use any of them, I’ll earn a commission.
In all honesty, these are some of the basic products that I use and recommend to everyone.
This Scotts Elite dual rotary spreader is not a professional grade model but it’s excellent for homeowners.
I really like the edge guard on it. It’s really easy to switch on and off so it’s great for going around my driveway and flower beds.
If you’re not looking to spend hundreds of dollars, I’d definitely recommend this model. It spreads out a wide path and is great quality for the cost.
This 4-Gallon sprayer is my absolute favorite. It sprays for a really long time. I’ve had this sprayer for quite a while and I’ve never had the battery run out.
The adjustable pressure switch is a really import feature to me.
You can order a lot of accessories for this model but I’ve never really found much of a need for it.
Hand aerators are great for small spots if you’ve got construction debris or a spot that constantly dries out.
You can also fill these holes with organic matter that will hold a bit more moisture.
This one by Yard Butler is an absolute bargain. It pulls nice long cores. I also use it for taking soil samples around the yard!