The Complete Guide to AMSOIL Fuel Additives
Modern fuel — both gasoline and diesel — isn't what it used to be. Pump gas now contains up to 10% ethanol (E10), which absorbs water and corrodes fuel-system components. Direct-injected gasoline engines spray fuel directly into the combustion chamber, so the fuel never washes the back of the intake valves and carbon deposits build up unchecked. Diesel fuel is now ultra-low sulfur (ULSD), which strips out the sulfur compounds that historically lubricated injection-pump and injector components — leaving high-pressure common-rail injectors exposed to wear they were never designed for.
AMSOIL fuel additives are formulated to attack these specific modern fuel problems at the chemistry level — restoring lost detergency, lubricity, cetane, and stability that today's pump fuels lack.
Gasoline: P.i.® for Deep Cleaning, UCL for Daily Protection
AMSOIL P.i. (Performance Improver) is the gold-standard gasoline detergent additive. Independent ASTM testing has shown P.i. restoring GDI fuel injectors to 100% flow rate after a single tank, and recovering up to 14% of horsepower lost to deposit buildup. Use it every 4,000 miles. Between deep-clean intervals, AMSOIL Upper Cylinder Lubricant (UCL) goes in every tank to add lubricity that ethanol-blended fuel doesn't provide and to fight ethanol-related corrosion in fuel pumps, injectors, and upper cylinders.
Powersports & Storage: Quickshot® and Gasoline Stabilizer
Motorcycles, ATVs, snowmobiles, marine outboards, lawn equipment, and generators sit unused for weeks or months at a time — and ethanol-blended fuel begins degrading almost immediately. Quickshot is engineered for the unique fuel-system challenges in powersports equipment that's been sitting. For longer storage windows up to 12 months, AMSOIL Gasoline Stabilizer prevents varnish, gum, and oxidation so the engine starts and runs cleanly when you put it back in service.
Octane Boost: DOMINATOR® and Motorcycle Octane Boost
When pump premium isn't quite premium enough — for tuned engines, towing under heavy load, or older high-compression motors — AMSOIL DOMINATOR Octane Boost adds up to 4 octane numbers to eliminate knock and unlock the timing advance modern ECMs hold back when they detect low-octane fuel. Motorcycle Octane Boost delivers up to 3 numbers in a 4 oz. bottle sized for bike, ATV, and small-tank powersports applications.
Diesel: Year-Round All-In-One or Targeted Single-Function Additives
For most diesel owners, AMSOIL Diesel All-In-One (4-IN-1) is the simplest path — it combines injector cleaning, cetane boost, cold-flow improvement, and lubricity in one bottle and is safe to use every tank, year-round. Owners who want targeted control can pick Diesel Injector Clean for concentrated cleaning, Diesel Injector Clean + Cetane Boost for cleaning plus combustion improvement, Diesel Cetane Boost for pure cetane increase, and Diesel Cold Flow specifically for winter anti-gel protection.
Diesel Recovery — When Prevention Wasn't Enough
Sometimes a cold snap arrives faster than the additive does, and the fuel gels in the tank or the filter freezes solid. AMSOIL Diesel Recovery is the rescue treatment — pour it in, let it work, and gelled fuel re-liquefies and frozen filters thaw without removal. It's alcohol-free and non-corrosive, safe for ULSD, off-road, and biodiesel. Keep a 30 oz. bottle in the truck through winter.
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Every product on this page links directly to AMSOIL.com with our dealer code attached. Order at retail, or enroll free in the Preferred Customer program to save 25% on every order with no minimums. Fast shipping from regional warehouses across North America.
