HTS heading 3811 · Chapter 38
HTS 3811: Antiknock preparations, oxidation inhibitors, gum…
HTS heading 3811 covers antiknock preparations, oxidation inhibitors, gum inhibitors, viscosity improvers, anti-corrosive preparations and other prepared additives, for mineral oils (including gasoline) or for other liquids used for the same purposes as mineral oils. It has 6 tariff lines with a duty rate; the general (MFN) rates are 6.5% (4 lines), Free (2 lines).
Imports may also owe Chapter 99 tariffs (Section 232, 301 or 201) depending on origin and date, plus the Merchandise Processing Fee and, by sea, the Harbor Maintenance Fee.
Rates from the 2026 HTS Revision 22, effective October 30, 2026. Source: U.S. International Trade Commission.
Tariff lines and duty rates
| HTS code | Description | General | Special | Column 2 | Estimate |
|---|---|---|---|---|---|
| Antiknock preparations: | |||||
| 3811.11 | Based on lead compounds: | ||||
| 3811.11.10.00 | Based on tetraethyl lead or on a mixture of tetraethyl lead and tetramethyl lead[kg] | Free | 30% | Estimate → | |
| 3811.11.50.00 | Other[kg] | Free | 25% | Estimate → | |
| 3811.19.00.00 | Other[kg] | 6.5% | Free (A+,AU,BH,CL,CO,D,E, IL,JO, KR,MA,OM,P, PA,PE,S,SG) | 3.7¢/kg + 60% | Estimate → |
| Additives for lubricating oils: | |||||
| 3811.21.00.00 | Containing petroleum oils or oils obtained from bituminous minerals[kg] | 6.5% | Free (A+,AU,BH,CL,CO,D, E,IL, JO,KR,MA,OM,P, PA,PE,S,SG) | 60% | Estimate → |
| 3811.29.00.00 | Other[kg] | 6.5% | Free (A+,AU,BH,CL,CO,D, E,IL, JO,KR,MA,OM,P, PA,PE,S,SG) | 25% | Estimate → |
| 3811.90.00.00 | Other[kg] | 6.5% | Free (A+,AU,BH,CL,CO,D, E,IL, JO,KR,MA,OM,P, PA,PE,S,SG) | 3.7¢/kg + 60% | Estimate → |
6 lines shown. Statistical suffixes (the last two digits) inherit the rate of the 8-digit subheading above them.
Example: base duty and fees on $10000
For HTS 3811.19.00.00 at the general rate of 6.5%, shipped by ocean, before any Chapter 99 tariffs:
| Base duty (6.5%) | $650.00 |
| Merchandise Processing Fee (0.3464%, min $34.58) | $34.64 |
| Harbor Maintenance Fee (0.125%) | $12.50 |
| Duty and fees | $697.14 |
Origin-specific tariffs can multiply this. Run this example from China or from Mexico to see every line.
Special program codes in this heading
- A, A*, A+
- Generalized System of Preferences (GSP)
- AU
- U.S.–Australia FTA
- BH
- U.S.–Bahrain FTA
- CL
- U.S.–Chile FTA
- CO
- U.S.–Colombia Trade Promotion Agreement
- D
- African Growth and Opportunity Act (AGOA)
- E, E*
- Caribbean Basin Economic Recovery Act
- IL
- U.S.–Israel FTA
- JO
- U.S.–Jordan FTA
- KR
- U.S.–Korea FTA (KORUS)
- MA
- U.S.–Morocco FTA
- OM
- U.S.–Oman FTA
- P, P+
- CAFTA-DR
- PA
- U.S.–Panama Trade Promotion Agreement
- PE
- U.S.–Peru Trade Promotion Agreement
- S, S+
- USMCA (United States–Mexico–Canada Agreement)
- SG
- U.S.–Singapore FTA
A special rate applies only when the goods qualify under that program's rules of origin and the claim is made at entry.