Most lawn mowers run best on regular unleaded gas with an octane rating of 87. Many people ask if they should use regular or premium gas for lawn mower engines. The quick answer—most mowers run best on regular 87-octane unleaded gas. I’ve tested regular, premium, and ethanol-free fuel in my own mower over several summers. The right gas can mean easier starts, smoother cuts, and fewer repairs.
Experts like Honda and Briggs & Stratton recommend fresh gas with no more than 10% ethanol. More ethanol can cause rust and carburetor problems. I’ve seen these issues first-hand when storing my mower over winter. In this guide, I’ll share what works, what to avoid, and when premium gas makes sense.
Why Gas Choice Matters for Lawn Mowers
The fuel you choose directly affects how well your mower runs and how long it lasts. Most push and riding mowers use 4-stroke lawn mower fuel, which means they have a separate oil system and burn straight gasoline. This is different from 2-stroke engines, which require an oil mix.
Octane rating matters because it shows how well fuel resists engine knocking. For small engines, like those in lawn mowers, 87 octane regular gas works best. Higher octane fuels, such as premium, are made for high-compression engines, so they rarely improve performance in standard mowers.
When buying gas for lawn mower at gas station, avoid fuel with more than 10% ethanol. Ethanol attracts water, which can cause rust and clog carburetors. Fresh, clean fuel keeps your engine starting easily and cutting smoothly. Choosing the right gas is not just about saving money—it’s about protecting your mower for years of reliable use.
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Regular Gas for Lawn Mower – The Pros and Cons
Advantages of Regular Gas (87 Octane)
Regular unleaded gas with an 87-octane rating is the standard choice for most 4-stroke lawn mowers. It’s affordable, easy to find, and works well for engines designed for low compression. After 4 years of using regular gas in my own mower, I’ve found it delivers consistent starts and smooth cutting without any loss in performance.
Another benefit is convenience. You can buy regular gas at almost any station without searching for special blends. For homeowners who mow once a week, this means less hassle and lower fuel costs over the season. When used fresh and stored correctly, regular gas is more than enough to keep your mower running well.
Drawbacks of Regular Gas
The main drawback is its shorter shelf life, especially when it contains ethanol. Many people ask, “Is it okay to use ethanol gas in a lawn mower?”—and the answer is yes, but with caution. Ethanol can attract moisture, which leads to corrosion, clogged carburetors, and hard starts after storage.
Regular gas with up to 10% ethanol is acceptable for most mowers, but it’s best to use it within 30 days or add a fuel stabilizer. If your mower sits unused for long periods, ethanol-free fuel is a safer choice. By being mindful of ethanol content, you can avoid the most common fuel-related engine problems.
Premium Gas for Lawn Mower – When It Makes Sense
Benefits of Premium Gas (91–93 Octane)
Premium gas has a higher octane rating, usually 91–93. This means it can resist knocking in high-compression engines. Many people ask, “Do lawn mowers run better on premium gas?” For most regular mowers, the difference is small.
In some high-performance or commercial mowers, premium fuel can burn a bit cleaner and run a little smoother. It may also help in tough situations, like mowing in very hot weather or under a heavy load. Higher octane fuel can leave fewer deposits inside the engine, which might extend the life of some parts.
Downsides of Premium Gas
The biggest drawback is cost. Premium gas costs more than regular, but most 4-stroke lawn mower engines do not need it. These engines are built to run on lower octane fuel, so the extra money often gives no real gain.
Availability can also be an issue. Not all gas stations offer ethanol-free premium fuel, which means you might still face ethanol-related storage problems. Unless your mower’s manual calls for premium, fresh 87-octane gas stored correctly is still the smartest and most affordable choice for most people.
Ethanol-Free Gas – The Third Option
Non ethanol gas for lawn mower engines is becoming a popular choice among homeowners and professionals. This fuel is pure gasoline without ethanol, which makes it more stable and less harmful to small engines. Many experts consider it the best gas for lawn mower ethanol-free because it avoids the problems that ethanol can cause.
One of the biggest benefits is a longer shelf life. Ethanol-free gas can stay fresh for months, making it ideal for seasonal equipment. It also absorbs far less moisture from the air, reducing the risk of rust, corrosion, and clogged carburetors. For mowers stored over the winter, this means fewer hard starts in spring.
You can buy ethanol-free gas at many hardware stores, marinas, and outdoor power equipment dealers. Some gas stations also carry it, but it may be labeled as “recreational fuel” or “marine fuel.” Special brands like TruFuel or VP Small Engine Fuel are sold in sealed cans for maximum freshness.
For official guidance, check the Briggs & Stratton Fuel Recommendations page, which explains why ethanol-free fuel is often the safest choice for small engines. While it may cost more, the reduced risk of engine damage and longer storage life can save you money on repairs and downtime in the long run.
Fuel Mixing and Additives
If you have a 2-stroke lawn mower, you must mix gasoline with 2-stroke engine oil before use. The exact ratio—often 50:1 or 40:1—depends on your mower’s manual. In contrast, 4-stroke lawn mower fuel does not require mixing; you simply add straight gasoline.
For long-term storage, consider adding a fuel stabilizer to your gas. Stabilizers slow down the breakdown of fuel and prevent varnish or gum buildup inside the carburetor. This is especially useful if you store your mower over the winter or don’t use it for several weeks.
Always mix stabilizer into fresh gas, not fuel that has already started to go stale. This helps keep the engine starting easily and running smoothly when the mowing season returns.
Regular vs Premium vs Ethanol-Free
Over four summers, I tested all three fuel types in my own mower. With regular gas, the mower started fine when fresh, but after a month in the shed, I noticed harder starts and a slightly rough idle. Cut quality stayed the same, but fuel left sitting too long caused minor carb issues.
Using premium gas, I didn’t see a big jump in cut quality or power. Starts were slightly smoother on hot days, but the difference didn’t match the higher cost. It felt more like a “nice to have” than a “need.”
With ethanol-free gas, the improvement was clear over time. Starts were effortless even after winter storage, and there was no stale fuel smell. The cut was consistent, and I didn’t need mid-season carb cleaning. While it cost more upfront, it saved me time and avoided repair bills—making it my preferred choice for long-term mower health.
Expert Opinions and Manufacturer Advice
Leading manufacturers like Honda Power Equipment, Toro, and Briggs & Stratton all recommend fresh, unleaded gasoline with an octane rating of 87 or higher for most 4-stroke mowers. They stress avoiding fuel with more than 10% ethanol, as higher ethanol levels can damage small engine components.
The EPA’s Small Engine Fuel Guidance also supports using fresh fuel, warning that stale or high-ethanol blends increase the risk of carburetor issues, poor starting, and reduced performance. They note that while premium gas is safe to use, it rarely provides measurable benefits unless the mower is designed for high compression.
Many manufacturer manuals suggest ethanol-free gas as the best option for long-term storage and reduced maintenance needs. This aligns with real-world results, especially for users who mow less often or store equipment for months at a time.
Learn more from the EPA’s official fuel guidance.
Final Verdict – My Fuel Choice for Lawn Mowers
After testing and reviewing expert advice, my top choice is ethanol-free regular gas for its reliability, long shelf life, and reduced maintenance costs.
For everyday mowing, 87-octane regular gas works well if you use it fresh and add a stabilizer for storage. Premium gas has niche benefits but isn’t worth the cost for most homeowners.
If you want to protect your mower, save on repairs, and enjoy easy starts—even after winter—ethanol-free fuel is the smartest long-term choice. “””
FAQs – Regular or Premium Gas for Lawn Mower
Q1: Should I use regular or premium gas for my lawn mower?
Most 4-stroke mowers run best on fresh 87-octane regular gas. Premium offers no big gain unless the manual says so.
Q2: Does a lawn mower use regular gas?
Yes. Most gas-powered mowers work fine with 87-octane unleaded gas, as long as it’s fresh and has under 10% ethanol.
Q3: Do lawn mowers run better on premium gas?
Not usually. Premium gas costs more and rarely improves performance unless your mower has a high-compression engine.
Q4: Is ethanol gas okay for a lawn mower?
Yes, if ethanol is 10% or less. Higher levels can cause rust, carb issues, and hard starts after storage.
Q5: What happens if you put regular gas in a lawn mower?
If it’s fresh 87-octane gas, nothing bad happens. It’s the standard fuel for most 4-stroke lawn mower engines.
Q6: Is ethanol-free gas better for lawn mowers?
Yes. Ethanol-free gas lasts longer, starts easier after storage, and helps prevent rust and carb problems.
Q7: Where can I buy ethanol-free gas for my lawn mower?
Find it at hardware stores, marinas, some gas stations, or buy sealed cans like TruFuel or VP Small Engine Fuel.
Q8: What’s the best gas for a lawn mower?
Fresh 87-octane gas with under 10% ethanol is best. For storage, ethanol-free gas offers longer life and fewer issues.
Q9: What do I mix with gas for a 2-stroke lawn mower?
Mix gas with 2-stroke engine oil, usually at 50:1 or 40:1. Check your mower’s manual for the exact ratio.
Q10: How long does lawn mower gas stay fresh?
Gas with ethanol lasts about 30 days. Ethanol-free gas can stay fresh for months when stored in a sealed container.
