Best Fuel Stabilizer for Ethanol Gas (2026)
Five fuel stabilizers for ethanol gas compared by treatment size, storage life, corrosion protection and engine fit, for mowers and yard gear in storage.
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Top picks at a glance
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- 1
Best OverallEthanol Shield Marine9.7/10View on Amazon - 2
Best Multi-PackSTA-BIL 12-Pack9.7/10View on Amazon - 3
Best ConcentratedStar Tron Stabilizer+9.6/10View on Amazon - 4
Bulk PickSTA-BIL 1 Gallon9.7/10View on Amazon - 5
Also ListedEthanol Shield 24 oz9.4/10View on Amazon - 6
VP Racing Fuels 2812 Madditive Fuel Stabilizer with EthanolView on Amazon - 7
STA-BIL 22208 Fuel StabilizerView on Amazon - 8
Quicksilver Quickstor Fuel Treatment and StabilizerView on Amazon - 9
Yamaha Yamalube Fuel Stabilizer & Conditioner- 32 OunceView on Amazon - 10
Yamaha Yamalube Fuel Stabilizer & Conditioner-View on Amazon
A mower that sits all winter with ethanol gas in the tank can greet spring with a gummed carburetor and a hard start, and the same goes for trimmers, blowers and any yard gear that rests between seasons. Treating stored gas before it sits keeps the fuel system clean and the engine ready to fire. This guide compares the best fuel stabilizer for ethanol gas by treatment size, storage life, corrosion protection and engine fit, for homeowners who store gas-powered yard gear.
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Quick picks
- Best Overall Ethanol Shield Marine: Treats 240 gallons per bottle with a 3X anticorrosive package. Check price on Amazon
- Best Multi-Pack STA-BIL 12-Pack: Keeps fuel fresh for up to 24 months and treats 20 gallons. Check price on Amazon
- Best Concentrated Star Tron Stabilizer+: Concentrated formula keeps fuel fresh for up to 2 years; treats 40 gallons total. Check price on Amazon
- Bulk Pick STA-BIL 1 Gallon: One gallon treats 320 gallons for large storage needs. Check price on Amazon
- Also Listed Ethanol Shield 24 oz: 24 oz 2-pack fuel stabilizer for ethanol gas. Check price on Amazon
Our acreage picks
Ethanol Shield MARINE Fuel Stabilizer and Preservative 2-Pack
A marine fuel stabilizer and preservative in a 2-pack of 24 oz bottles, each treating 240 gallons, with a P.E.A. based detergent, phase separation inhibitor and 3X anticorrosive package.
Read the full review
The marine Ethanol Shield leads this group on stated protection. Its listing states a proprietary top tier P.E.A. based detergent that keeps the carburetor and injectors clean and prevents carbon and varnish build-up, plus a 3X anticorrosive package and a 2X antioxidant package.
One contradiction needs noting: the spec table lists a unit count of 4.48 fluid ounces, while the item volume states 24 fluid ounces and the title states 2-24 oz bottles. The title and bullets win here, so this article follows the 24 oz bottle figure. No storage duration and no warranty term are stated.
Pros
- Each bottle treats 240 gallons, the largest per-bottle figure here
- 3X anticorrosive package with top level ASTM and NACE ratings stated
- Phase separation inhibitor helps remove water
- P.E.A. based detergent keeps carburetor and injectors clean
Cons
- No storage duration stated
- Spec table unit count of 4.48 fluid ounces conflicts with the 24 fluid ounces item volume and the title
- No warranty term stated
- Two-pack size may be more than a single mower owner needs
STA-BIL Storage Fuel Stabilizer 8 oz 12-Pack
A storage fuel stabilizer in a 12-pack of 8 oz bottles that keeps gasoline fresh for up to 24 months and protects against corrosion and ethanol damage.
Read the full review
The STA-BIL 12-pack is the storage specialist here. Its listing states fuel kept fresh for up to 24 months for vehicles not in use, boats and outdoor power equipment during winter months, plus removal of water to prevent corrosion and cleaning of carburetors and fuel injectors.
The title states treats 20 gallons beside directions that state 1 oz per 2.5 gallons, so the treats figure reads per bottle; check the bottle size before buying. The warranty description states only a satisfaction pledge with no concrete term, so this article scores warranty at zero.
Pros
- Keeps fuel fresh for up to 24 months during storage
- Removes water to prevent corrosion and cleans carburetors and fuel injectors
- Protects against gum, varnish, rust and corrosion
- Fits all 2-cycle and 4-cycle gasoline engines
Cons
- Warranty description states only a satisfaction pledge, with no concrete term
- Title treats figure of 20 gallons sits beside directions of 1 oz per 2.5 gallons, so check the bottle size before buying
- 12-pack may be more than a single mower owner needs
- Item weight of 6.6 pounds for the pack
STA-BIL Storage Fuel Stabilizer, 1 Gallon (Treats 320 Gallons)
Bulk 1-gallon STA-BIL Storage bottle that treats 320 gallons and states fuel stays fresh up to 24 months during storage.
Who it's for: owners treating several machines or stocking fuel for the season.
Who should skip it: anyone with a single pressure washer, where the 10 oz bottle fits better.
Read the full review
The STA-BIL Storage gallon is the bulk pick here: the title says 1 gallon treats 320 gallons and the bullets say fuel stays fresh up to 24 months during storage. Directions are complete on the listing: pour into the tank before adding gasoline, use 1 oz per 2.5 gallons, then run the engine 5 minutes to treat the system. The spec table notes the opened product is good for 2 years, and the warranty line is a satisfaction guarantee with no term.
Pros
- Treats 320 gallons from a single 1-gallon bottle
- States fuel stays fresh for up to 24 months
- Gives full directions: 1 oz per 2.5 gallons, run the engine 5 minutes
- Claims protection against corrosion and ethanol damage
Cons
- The 1-gallon size is more than one pressure washer needs in a season
- Warranty Description offers only a satisfaction guarantee, with no term stated
- An opened bottle is good for 2 years, so a gallon may expire before it is used up
- The 128 fl oz bottle takes more shelf space than the smaller picks
STAR BRITE STAR TRON STABILIZER Plus Fuel Storage and Corrosion Protection
A concentrated stabilizer with enzymes and corrosion inhibitors that keeps fuel fresh for up to 2 years and treats 40 gallons total from an 8 oz bottle.
Read the full review
Star Tron is the concentrated pick. Its listing states enzymes that stabilize fuel and break down contaminants like gum, varnish and moisture, plus corrosion inhibitors that protect metal surfaces against internal rust. It states use in all gas engines for motorcycles, boats, lawn equipment and classic cars, with pouring directly into the tank and no extra steps.
One contradiction needs noting: the bullets state 1 oz treats 5 gallons, while the spec table states 1 ounce treats 6 gallons. The bullets win here, so this article follows the 5 gallon figure. The warranty description states only the word Warranty with no term, so this article scores warranty at zero.
Pros
- Enzymes stabilize fuel and break down gum, varnish and moisture
- Corrosion inhibitors protect metal surfaces against internal rust
- Works with all ethanol blends and non-ethanol gasoline
- One ounce treats 5 gallons, with 8 oz treating 40 gallons total
Cons
- Bullets state 1 oz treats 5 gallons while the spec table states 1 ounce treats 6 gallons
- Warranty description states only the word Warranty, with no term
- Not recommended for diesel fuel
- Single 8 oz bottle treats less total fuel than the larger packs here
Ethanol Shield Fuel Stabilizer, 24 oz (2 Pack)
Ethanol Shield Fuel Stabilizer as a 24 oz 2-pack with stated antioxidant, anticorrosive and phase separation claims, for 2-cycle and 4-cycle engines.
Read the full review
The 24 oz 2-pack splits the treatment across two bottles, which suits a shed and a garage can, or a mower and a blower. The listing states antioxidant and anticorrosive action, phase separation inhibition, and use in 2-cycle and 4-cycle engines.
Pros
- Two 24 oz bottles instead of one large one
- States 2-cycle and 4-cycle use
- States antioxidant, anticorrosive and phase separation claims
- Upper-cylinder lubrication and rubber protection are named
Cons
- No treat rate in gallons is stated
- No storage term is stated
- No warranty term is stated
- No safety certification is stated
Other machines to compare
VP Racing Fuels 2812 Madditive Fuel Stabilizer with EthanolCheck price on Amazon
STA-BIL 22208 Fuel StabilizerCheck price on Amazon
Quicksilver Quickstor Fuel Treatment and StabilizerCheck price on Amazon
Yamaha Yamalube Fuel Stabilizer & Conditioner- 32 OunceCheck price on Amazon
Yamaha Yamalube Fuel Stabilizer & Conditioner-Check price on Amazon
Side-by-side specs
| Model | Acre Score | Treats | Freshness | Engines | Corrosion protection |
|---|---|---|---|---|---|
| Ethanol Shield Marine | 9.7/10 | 240 gallons per bottle | Not stated | 2 and 4 cycle, all gasolines | 3X anticorrosive package |
| STA-BIL 12-Pack | 9.7/10 | 20 gallons | Up to 24 months | 2-cycle and 4-cycle gasoline engines | Protects against corrosion |
| Star Tron Stabilizer+ | 9.6/10 | 40 gallons total | Up to 2 years | All gas engines; not diesel | Corrosion inhibitors |
| STA-BIL 1 Gallon | 9.7/10 | 320 gallons | Not stated | Not stated | Not stated |
| Ethanol Shield 24 oz | 9.4/10 | Not stated | Not stated | Not stated | Not stated |
Specifications are manufacturer rated as listed, collected 28 October 2026.
Acreage and terrain fit
Ethanol Shield Marine
STA-BIL 12-Pack
Star Tron Stabilizer+
STA-BIL 1 Gallon
Ethanol Shield 24 oz
Buying guide: best fuel stabilizer for ethanol gas
Treatment size
Match the bottle to the fuel on hand. The listings here range from a 12-pack of 8 oz bottles that treats 20 gallons per the title, to a single gallon that treats 320 gallons, with a marine 2-pack at 240 gallons per bottle and a concentrated 8 oz bottle that treats 40 gallons total.
Storage life
Storage life decides how long treated fuel stays usable. One listing keeps fuel fresh for up to 24 months during storage, and another keeps fuel fresh for up to 2 years. The remaining listings state no storage duration, so check the bottle before counting on a full off-season. For winter storage specifically, see the best fuel stabilizer for winter storage.
Ethanol and water
Ethanol blends draw moisture, and the listings here answer that in different ways. Some state they remove water to prevent corrosion, one states a phase separation inhibitor that helps remove water, and one states corrosion inhibitors that protect metal surfaces. A stabilizer that states both water removal and corrosion protection covers the two main ethanol storage problems at once.
Engine fit
Check engine fit before buying. The full-data listings state fit for 2-cycle and 4-cycle gasoline engines, and one states it works in all gas engines while noting it is not recommended for diesel fuel. For mower-specific picks, see the best fuel stabilizer for lawn mowers. The title-only listings state no engine fit, so confirm fit on the listing before buying.
Matching It to Your Property
- One mower and one gas can: a small bottle that treats 20 gallons or 40 gallons total covers a season of storage.
- Several gas machines across a large property: a gallon that treats 320 gallons keeps every tank treated from one bottle.
- Marine and wet storage: a phase separation inhibitor and water removal matter most where moisture reaches the tank.
- Winter layup: pour the stabilizer into the tank before adding gasoline, then run the engine so the treated fuel reaches the whole system, per the STA-BIL directions.
Read the manual, keep children and pets out of the yard while you work, wear eye and hearing protection and sturdy footwear, and never exceed the slope rating of your machine. Refuel only with the engine off and cool. See CPSC lawn mower safety. Read our Safety Disclaimer.
The Acre Score explained
The Acre Score weighs performance, build, value, safety and warranty, using only what each listing publishes. A listing that states no warranty term gets zero for warranty, and the score tables show the rest. The weights are on our How We Pick page.
| Product | Acre Score | Perf. /35 | Build /25 | Value /25 | Safety /10 | Warranty /5 |
|---|---|---|---|---|---|---|
| Ethanol Shield Marine | 9.7 | 32 | 22 | 22 | n/a | 0 |
| STA-BIL 12-Pack | 9.7 | 30 | 22 | 21 | n/a | 0 |
| Star Tron Stabilizer+ | 9.6 | 30 | 20 | 22 | n/a | 0 |
Scores run from 9.2 to 9.8: each product’s point total is placed on that range, so more points always means a higher score. Safety counts only for powered gear or where the listing states safety features; where it does not apply, the score is taken over the remaining 90 points.
FAQ: mowing large lots
How much stabilizer do I add to a tank?
Follow the listing directions: the STA-BIL listing states 1 oz for every 2.5 gallons of gas, and the Star Tron listing states 1 oz treats 5 gallons. Pour the stabilizer into the tank before adding gasoline, per the STA-BIL directions.
Does stabilizer work in ethanol gas?
Yes, per these listings: one states it can be used with all ethanol blends and non-ethanol gasoline, and another states protection against the effects of both ethanol and non-ethanol fuels. The marine listing states it covers all gasolines, with or without ethanol.
How long does treated fuel stay fresh?
One listing states up to 24 months during storage, and another states up to 2 years. The remaining listings state no storage duration, so do not assume a full off-season from them.
Can I use a marine stabilizer in a mower?
The marine listing states it covers all engines, 2 and 4 cycle, and all gasolines, so it fits mower engines on the listing’s own terms. Check the treatment size against the tank before buying.
Do I need to drain fuel before storage?
The STA-BIL listing states its stabilizer eliminates the need to drain fuel before storage. Other listings state no such claim, so follow the listing for the bottle in hand.
More mowing guides
See the mower maintenance hub and the riding mower maintenance guide for the rest of the off-season routine.
