AMSOIL Fuel Additive Dose Calculator
Calculate the precise amount of AMSOIL fuel additive you need for any tank — gasoline (P.i., Quickshot, Gasoline Stabilizer, Upper Cylinder Lubricant) and diesel (Diesel All-In-One, Diesel Injector Clean, Diesel Cold Flow, Diesel Cetane Boost).
Fuel Additive Dose Calculator
Pick a product, enter your tank size, and the calculator returns the exact ounces of additive — and how many bottles to bring.
Auto-fills from the selected product. Override only if you have a specific application instruction.
Pour this much additive
8.0 oz
1 bottle (12 oz) · Every 4,000 miles
Common AMSOIL Fuel Additive Ratios
Reference treat rates for every AMSOIL fuel additive in this calculator.
| Product | Fuel | Treat ratio | Bottle size | Treats up to |
|---|---|---|---|---|
| P.i. Performance Improver | Gasoline | 1 oz / 2.5 gal | 12 oz bottle | 30 gal |
| Quickshot | Gasoline | 1 oz / 1.5 gal | 8 oz bottle | 12 gal |
| Gasoline Stabilizer | Gasoline | 1 oz / 2.5 gal | 16 oz bottle | 40 gal |
| Upper Cylinder Lubricant | Gasoline | 1 oz / 4.2 gal | 6 oz bottle | 25 gal |
| Diesel All-In-One | Diesel | 1 oz / 2.5 gal | 16 oz bottle | 40 gal |
| Diesel Injector Clean | Diesel | 1 oz / 5 gal | 16 oz bottle | 80 gal |
| Diesel Cold Flow | Diesel | 1 oz / 5 gal | 16 oz bottle | 80 gal |
| Diesel Cetane Boost | Diesel | 1 oz / 10 gal | 8 oz bottle | 80 gal |
Quickshot rates shown for ongoing maintenance dosing (8 oz / 12 gal). Use the calculator below for the heavier 8 oz / 6 gal initial clean-up dose.
AMSOIL Fuel Additives — How Do They Help?
Modern engines are far more sensitive to fuel quality than the engines they replaced. Direct-injection gasoline engines build intake-valve deposits that conventional in-tank detergents can't reach. ULSD diesel fuel has lower lubricity than the high-sulphur diesel that came before it, increasing pump and injector wear. Ethanol-blended pump gasoline absorbs water out of the air, gums carbs and shortens shelf life. AMSOIL fuel additives are the post-pump solutions to each of these problems — engineered chemistry, validated by clinical testing, dosed by the calculator above.
Gasoline additives
- P.i.® Performance Improver — the most effective gasoline detergent sold over the counter. Cleans injectors, intake valves and combustion chambers in a single tank. Restores up to 14% horsepower and 5.7% fuel economy in clinical testing.
- Quickshot® — fixes ethanol-related performance issues in small engines, powersports and marine. Use the heavier clean-up dose initially (8 oz / 6 gal), then maintenance (8 oz / 12 gal) thereafter.
- Gasoline Stabilizer — extends shelf life of stored gasoline up to 12 months. The right call for snowblowers, mowers and seasonal toys at end-of-season.
- Upper Cylinder Lubricant — adds top-end lubricity and intake-valve protection to every tank. Especially valuable for direct-injection engines that don't get the natural valve-wash of port-injected designs.
Diesel additives
- Diesel All-In-One — single-bottle year-round diesel treatment. Combines cetane boost, lubricity, cold-flow improvement and detergency. The simple choice for daily-driver diesels.
- Diesel Injector Clean — restores injector flow, cuts smoke, recovers MPG. Adds critical lubricity to ULSD.
- Diesel Cold Flow — improves cold-weather operability. Lowers cold-filter plugging point and pour point so trucks start and run in extreme cold.
- Diesel Cetane Boost — raises fuel cetane up to 8 numbers for easier starts, smoother idle, less smoke and better throttle response.
Fuel Additive FAQs
Can I run P.i. every tank?
You can, but you don't need to. AMSOIL's clinical testing shows P.i. restores near-new injector flow and combustion-chamber cleanliness in a single tank. Running it once every 4,000 miles (or every 3–4 months) is enough for most gasoline engines. Use Upper Cylinder Lubricant or Gasoline Stabilizer for every-tank maintenance.
What's the difference between the Quickshot clean-up dose and the maintenance dose?
AMSOIL specifies an initial clean-up dose of 8 oz per 6 gallons of gasoline (about 1.33 oz/gal) when you first introduce Quickshot to a problem fuel system, then drops back to 8 oz per 12 gallons (about 0.67 oz/gal) for ongoing maintenance. The calculator above lets you toggle between the two modes.
Do I still need Diesel Cold Flow if I'm running Diesel All-In-One?
No. Diesel All-In-One already contains the cold-flow chemistry from Diesel Cold Flow plus the cetane boost from Diesel Cetane Boost and the detergency from Diesel Injector Clean. Run a second bottle only in extreme cold or for a heavier one-time clean-up dose.
Is it OK to over-treat?
Running a slightly rich dose (up to 2× the label rate) is safe for a one-time cleanup, but ongoing over-treatment wastes money and can give diminishing returns. Under-treating — pouring the same bottle into a larger tank than it's rated for — is the more common mistake this calculator prevents.
Can I pre-mix the additive before fueling?
Yes. Pouring the additive into the tank first, then fueling on top of it, mixes it thoroughly without any effort on your part. Avoid splashing concentrated additive onto painted surfaces.
Why does the calculator tell me "bottles needed" as a whole number?
Most users will pour a full bottle — it's more practical than measuring out a partial bottle at the pump. The calculator rounds up so you know how many bottles to bring for a full treatment; the "ounces needed" output is the exact dose for anyone who wants to measure.
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Independent AMSOIL Dealer #1858536. This calculator is for reference only — always defer to your equipment manufacturer's specifications. Inputs stay in your browser; nothing is submitted, stored or logged.