Rough Idle or Lost Performance
Start with P.I. when deposits may be affecting injector flow, throttle response, combustion or fuel economy.
Learn About AMSOIL P.I. →
Gasoline Fuel Additives · USA & Canada
AMSOIL Gasoline Fuel Additives
Clean injectors, protect against ethanol-related corrosion, stabilize stored fuel and solve the fuel problems that affect cars, trucks, motorcycles, boats and power equipment.
Quick Answer
Use P.I. Performance Improver for a concentrated fuel-system cleaning. Use Upper Cylinder Lubricant regularly for added lubricity and corrosion protection. Use Gasoline Stabilizer before storage. Use Quickshot in motorcycles, boats, ATVs, snowmobiles and small engines that face ethanol, moisture and seasonal-storage problems.
Start With the Problem
Clean
Protect
Store
Powersports
What Do You Need the Additive to Do?
Fuel additives are not interchangeable. A cleaner, lubricant, stabilizer and octane booster each have a different job. Pick the problem first, then pick the bottle.
Daily Fuel-System Protection
Upper Cylinder Lubricant adds lubricity and helps protect fuel-system metal from corrosion, including corrosion associated with ethanol-blended fuel.
See Upper Cylinder Lubricant →Seasonal or Long-Term Storage
Treat fresh gasoline before parking a vehicle or machine. Stabilizer helps fuel resist deterioration during storage.
See Gasoline Stabilizer →Ethanol and Moisture Trouble
Quickshot is the targeted choice for powersports and small-engine fuel systems exposed to ethanol, moisture and irregular use.
See Quickshot →
Product Selector
AMSOIL Gasoline Additive Lineup
These products overlap slightly, but each one has a main purpose. You do not need to pour every additive into every tank.
P.I. Performance Improver
A concentrated cleaner for gasoline injectors, combustion deposits and deposit-related performance loss.
- Best for cars and light trucks
- Use every 4,000 miles (6,400 km)
- One bottle treats up to 20 gallons
Upper Cylinder Lubricant
A regular-use gasoline additive designed to improve lubricity, help maintain cleanliness and fight fuel-system corrosion.
- Best for routine protection
- Useful with ethanol-blended gasoline
- Add at fill-up as directed
Gasoline Stabilizer
Protects stored gasoline from deterioration so seasonal vehicles and equipment are easier to start when they return to service.
- Best for storage
- Treat fresh gasoline before parking
- Run the engine to circulate treated fuel
Quickshot
Fuel-system treatment for motorcycles, boats, ATVs, snowmobiles and small engines that may sit, collect moisture or run ethanol-blended fuel.
- Best for powersports and equipment
- Targets ethanol and moisture problems
- Helps clean carburetors and injectors
DOMINATOR Octane Boost
Raises gasoline octane for engines that need greater resistance to detonation. It is not a substitute for the fuel grade required by the manufacturer.
- Best for performance applications
- Use only when more octane is needed
- Not a general fuel-system cleaner
Side-by-Side
Gasoline Fuel Additive Comparison
| Product | Main Job | Best Use | Not the Right Choice For |
|---|---|---|---|
| P.I. Performance Improver | Concentrated deposit cleaning | Cars and trucks with deposit-related symptoms or scheduled maintenance | Fuel storage |
| Upper Cylinder Lubricant | Lubricity, cleanliness and corrosion protection | Regular treatment in gasoline vehicles | Heavy deposit removal or octane increase |
| Gasoline Stabilizer | Slows fuel deterioration in storage | Seasonal vehicles, generators and stored equipment | Cleaning a dirty running engine |
| Quickshot | Ethanol, moisture and fuel-system protection | Powersports, marine and small engines | Raising octane |
| DOMINATOR Octane Boost | Raises octane | Performance engines needing more knock resistance | Routine cleaning or storage |
Mechanic's Advice
When an Additive Helps—and When It Won't
Good First Step
An additive makes sense when symptoms point toward deposits, stale fuel, moisture or corrosion and the engine is otherwise mechanically sound.
Not a Mechanical Repair
No bottle will repair a failed fuel pump, plugged filter, damaged injector, worn piston rings, ignition fault, vacuum leak or bad sensor.
Diagnose Persistent Problems
If a check-engine light, misfire, hard start or loss of power remains after treatment, scan and test the system instead of repeatedly adding more chemical.
Buy From the Mechanic. Not the Salesman.
Vyscocity is an independent authorized AMSOIL dealer serving the USA and Canada. Purchases are completed securely on AMSOIL.com with dealer code 1377814 applied.
Straight Answers
Gasoline Fuel Additive FAQ
Which AMSOIL gasoline additive should I use?
Use P.I. for concentrated cleaning, Upper Cylinder Lubricant for regular lubricity and corrosion protection, Gasoline Stabilizer for storage, Quickshot for powersports and small-engine fuel problems, and DOMINATOR Octane Boost when the engine specifically needs more octane.
Can I use P.I. and Upper Cylinder Lubricant together?
Yes. They do different jobs: P.I. is the concentrated cleaner, while Upper Cylinder Lubricant is intended for ongoing protection and lubricity. Follow the label dosage for each product.
Do gasoline additives fix rough idle and poor fuel economy?
They can help when deposits or degraded fuel are the cause. They cannot repair mechanical, electrical or ignition faults. Persistent symptoms need proper diagnosis.
Do I need a fuel additive if I buy TOP TIER gasoline?
TOP TIER fuel contains a higher detergent package than the minimum requirement and is a good everyday choice. A concentrated treatment can still be useful for corrective cleaning, storage or application-specific protection.
What should I add before storing a gasoline engine?
Add Gasoline Stabilizer to fresh fuel before storage, then run the engine long enough to move treated fuel through the system. Quickshot may be the better application-specific choice for powersports, marine and small engines.
Can these products be used in diesel fuel?
No. These products are formulated for gasoline applications. Use an AMSOIL diesel fuel additive selected for the diesel problem you are trying to solve.
Where can I buy AMSOIL gasoline fuel additives?
You can buy them directly from AMSOIL through the links on this page. The Vyscocity dealer code is already included, and AMSOIL handles pricing, checkout and shipping.