A partial-volume example
For 15 US gallons, 15 divided by 5 gives 3 fl oz. Calculate from the quantity requiring treatment, not automatically from the tank's full capacity. Check prior additions when the tank already contains treated fuel.
Compare package coverage
At that same rate, a 16 fl oz container corresponds to 80 US gallons of treatment. Use coverage when comparing packaging and current prices, while also considering how conveniently you can measure and store it.
Keep product notes separate
Do not reuse a note headed 4-IN-1 or Cetane Boost. Each product has its own directions. For shared trucks, put the exact product name at the top and cross out superseded notes.
Check the official directions
Use the current package label and manufacturer documents for treatment rates, handling and application details.
Independent dealer link. Current price and availability are shown by AMSOIL.
Practical checklist
- Determine US gallons being treated.
- Divide that number by 5.
- Record the product and measured amount.
Questions before you buy
How much for 30 US gallons?
The published maintenance-rate calculation gives 6 fl oz. Check the label before use.
Should I measure by tank capacity?
Only if that is the fuel volume requiring treatment. Partial fills and previous treatment need to be accounted for.
Related questions and products
- 4-IN-1 treatment ratios
- Cetane Boost dosing
- When to add diesel anti-gel
- AMSOIL Diesel 4-IN-1 Fuel Additive
- AMSOIL Diesel Cetane Boost Fuel Additive
Prepared by SyntheticOilHQ, independent AMSOIL dealer 313120. Product information checked October 16, 2026. Consult the current manufacturer label for application details.