Priced as of May 25, 2026
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Prices may varySerious hazard — read before use
The manufacturer's Safety Data Sheet classifies this product with one or more GHS Category 1 health hazards — the most severe tier. The hazard statements in quotes below are the verbatim GHS language from the SDS, as required by OSHA's Hazard Communication Standard. The line under each statement translates the GHS classification into plain language.
- H304 “May be fatal if swallowed and enters airways.”
GHS Category 1 aspiration toxicity — thin, oily liquids can slip into the lungs if swallowed, causing chemical pneumonia.
If swallowed, inhaled, or splashed in eyes:
Call Poison Control immediately at 1-800-222-1222 (US, 24/7, free) and have the product container with you. Poison Control's standing guidance is to not induce vomiting after chemical exposure; they will direct first-aid steps based on the specific product.
About this product's hazards. This product's Safety Data Sheet uses signal word danger. Read the manufacturer's SDS and follow all safety instructions before use. CarCareTruth ratings translate the manufacturer's safety sheet. They do not replace the SDS or substitute for a hazard assessment specific to your task.
The Podium · Top 3 in Fuel Stabilizer
See the full ranking →This product ranks #1 of 7 in Fuel Stabilizer.
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CarCareTruth's Analysis
Last reviewed May 25, 2026
TL;DR Community evidence going back 15+ years confirms multi-year fuel preservation — storage beyond 3 seasons is documented across collector cars, boats, generators, and small engines. The 1 oz per 16 gallon treatment ratio is the best in the category, making the 32 oz bottle practical for large fuel reserves. The SDS assigns a DANGER signal word from H304 (aspiration hazard); do not induce vomiting if ingested — seek medical attention.
What it is and how it performs
PRI-G is a super-concentrated petroleum-based gasoline treatment from Power Research Inc. designed to preserve stored fuel in refinery-fresh condition. The manufacturer claims multi-year protection with annual re-treatment; independent community evidence backs this up. Verified Amazon reviewers cite 3-year, 5-year, and 15-year consistent-use histories across seasonal small engines, classic vehicles, boats, and generators. The formula is labeled explicitly for E10 — the most common US pump grade — and community reviews confirm no phase separation or degradation failures in E10 use. At 1 oz per 16 gallons, a 32 oz bottle covers 512 gallons.
Who should buy this — and who should skip it
Best for seasonal small-engine owners, classic car and motorcycle collectors, boat owners, and anyone storing fuel for more than one season who needs documented multi-year performance. Also suited for large fuel reserves (55-gallon drums, generator stockpiles) where the exceptional treatment ratio keeps per-gallon cost low. Skip it if you are only storing fuel for a month or two — fresh fuel over short durations does not degrade enough to require stabilization.
Safety and environmental impact
The GHS hazard codes derived from the SDS assign a DANGER signal word driven by H304 (aspiration hazard Cat 1 — the petroleum distillate base can cause severe lung injury if swallowed and aspirated into the airways). H335 (respiratory irritation) and H351 (suspected carcinogen Cat 2 from experimental animal skin-tumor data) are also present at mixture level. PPE tiers translated from these codes: lungs recommended in enclosed or poorly ventilated spaces (H335 combined with petroleum distillate VOC), skin situational for the concentrate pour step (H315). Eyes are not required — the MSDS states the product is essentially non-irritating to eyes. Do not induce vomiting if ingested; seek medical attention immediately. The product is burned with treated fuel — dispose of unused concentrate through a fuel or chemical recycling program.
Frequently asked questions
How long does PRI-G actually keep fuel fresh?▾
Community evidence from small-engine owners, classic car enthusiasts, and preparedness communities consistently documents reliable protection for 12+ months with a single treatment, and multi-year protection when the fuel is re-treated annually. Verified Amazon reviewers cite 3-year, 5-year, and 15-year consistent-use histories. The manufacturer claims refinery-fresh preservation for years with annual re-treatment — community evidence corroborates multi-year performance at a level unusual for this category.
Does PRI-G work with ethanol-blended fuel (E10)?▾
The label explicitly states 'IDEAL FOR E-10 GASOLINE.' Community reviewers confirm reliable performance with standard E10 pump gas across multiple storage seasons, including a May 2026 verified review documenting 6-month E10 storage with no degradation. The 2003 MSDS does not disclose a specific ethanol stabilizer active chemistry (the amine fraction CAS is not established), so E10 compatibility is confirmed by label language and community evidence.
What is the correct treatment ratio for PRI-G?▾
The standard maintenance dose is 1 oz per 16 gallons. A 32 oz bottle treats up to 512 gallons; a 16 oz bottle treats up to 256 gallons. For restoring degraded fuel, a higher dose can be used — multiple reviewers report good results at 4x the standard rate with no engine harm.
Is PRI-G safe for 2-stroke engines?▾
Yes. The label explicitly states 'FOR ALL 2 & 4 STROKE ENGINES.' PRI-G is used in small 2-stroke engines (chainsaws, trimmers, outboard motors) as well as 4-stroke engines. It is formulated for gasoline only — PRI-D is the separate formula for diesel applications.
Does PRI-G contain California Prop 65 substances?▾
The 2003 MSDS §15 explicitly states the product does not require a Prop 65 warning, and Amazon's listing confirms no Prop 65 warning. However, the MSDS is over 20 years old and California's Prop 65 list has expanded since then. A current GHS-format SDS from Power Research Inc. may reflect updated status — contact usa@priproducts.com for the latest documentation.
From the manufacturer
Marketing copy from PRI-G, via Amazon. Not editorial.
- •32 ounce bottle and treats up to 512 gallons
- •Provides improved fuel economy - 5 to 15%
- •Preserves stored fuels in refinery fresh condition for years
- •Improves power output
- •Reduces HC and NOx emissions
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Manufacturer videos
Manufacturer specifications
- Manufacturer
- Power Research Incorporated
- Brand
- PRI
- Model
- PRI 32G
- Item Weight
- 1.83 pounds
- Product Dimensions
- 4.25 x 2.75 x 9 inches
- Item model number
- PRI-G-32V
- Is Discontinued By Manufacturer
- No
- Manufacturer Part Number
- PRI-G-32V
- ASIN
- B009TWQAOA
- Customer Reviews
- 4.8 4.8 out of 5 stars (1,017) 4.8 out of 5 stars
- Best Sellers Rank
- #4,751 in Automotive (See Top 100 in Automotive) #10 in Diesel Additives
- Date First Available
- February 22, 2012
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Top Amazon review
↗External — Amazon's most-helpful review for context.
The best fuel stabilizer and treatment on the market, bar none.
There is absolutely no better product for either gasoline or diesel fuel treatment or remediation on the market that I have found. It just works better than anything else. I know for a fact that fuel that I have stabilized for over 3 years that has been refreshed with an additional dose of this product runs better and cleaner and carbureted power equipment than fresh non-ethanol fuel without fuel stabilizer. I have the carburetor bowls and the spark plugs and the mechanical repair experience to prove it. This is without exception my favorite fuel additive. I buy this and use it religiously, because it just works so well. It has never let me down and over 15 years of consistent use. Other products have. This size bottle is going to be your best value for the money, and I always recommend buying it in much larger quantities than you think you'll ever need or use, because you will need it. The only downside to this bottle, is that it is somewhat easy to over treat and waste product. Fortunately, there is absolutely no issue with over treating at all.