API SQ is the current API gasoline engine-oil category, introduced for licensing on March 31, 2025. API says SQ oils can provide the performance of earlier gasoline categories and may be used where earlier categories are recommended. That does not mean the API letters are the only compatibility check.
Check another API, ILSAC, diesel or ACEA pair with the Engine Oil Standard Compatibility Checker.
Keep the SAE viscosity and every vehicle-manufacturer requirement from the manual. Specialty, racing, vintage, and unusual applications may need guidance outside the ordinary passenger-car category.
Watch: API SQ and Older Cars
Editorial correction: the video and original article treated classic-car zinc needs as one universal cutoff. Camshaft design, engine modifications, viscosity, and manufacturer guidance vary, so use the narrower compatibility method below.
API SQ versus API SP at a glance
| Category | Licensing date | API consumer guidance |
|---|---|---|
| API SP | May 1, 2020 | Introduced protection requirements including LSPI, timing-chain wear, deposits, and related performance |
| API SQ | March 31, 2025 | Current category with added or updated performance requirements; can service earlier-category recommendations under API guidance |
API’s Motor Oil Guide is the controlling source for the category-level summary. Do not substitute an aftermarket chart that invents a repair-price outcome or a universal engine-year cutoff.
What changed with API SQ
API describes SQ as addressing current engine and emissions-system needs and associates it with ILSAC GF-7A and GF-7B oils. The guide identifies performance areas such as fuel economy, emissions-system protection, and control of low-speed pre-ignition and timing-chain wear.
Those are standardized category requirements—not proof that every SQ product is identical, nor proof that SQ replaces an OEM approval such as dexos, Ford WSS, VW, Mercedes-Benz, or BMW Longlife.
Can you use API SQ when the manual says SP or SN?
For an ordinary gasoline passenger-car application that calls for an earlier API S category, API’s guide says the latest category includes the performance properties of earlier categories and may be used where they were recommended.
Still complete these checks:
- Match the full SAE grade, such as 0W-20 or 5W-30.
- Match the required API or ILSAC mark and viscosity limitations.
- Match any manufacturer specification or formal approval.
- Check the manual for an explicit exception, special oil, or vintage-engine requirement.
If any check conflicts, the exact vehicle or engine guidance wins.
Classic and modified engines need their own evidence
Do not assume every pre-1990 engine needs the same zinc concentration, or that every flat-tappet engine can use one racing oil. Valvetrain design, spring pressure, break-in procedure, catalytic-converter requirements, viscosity, and builder instructions can all matter.
For an original engine, start with the manufacturer publication. For a rebuilt or modified engine, use the engine builder’s documented oil and break-in requirements. API SQ’s passenger-car compatibility statement is not a substitute for that application-specific evidence.
Price and interval are separate questions
API does not set retail prices in the Motor Oil Guide, so SQ should not be described as universally equal in price to SP. Compare the exact bottle size, product, licensing, and local price.
The category also does not reset or extend the oil-change interval. Follow the vehicle’s schedule or oil-life system; our oil-change timing guide explains the decision order.
Frequently Asked Questions
Is API SQ better than API SP?
SQ is the newer category with updated performance requirements. “Better” does not mean compatible with every vehicle unless viscosity and all manufacturer requirements also match.
Will API SQ cause leaks in a high-mileage engine?
The category label alone cannot diagnose or guarantee leak behavior. Inspect active leaks and choose a product that matches the engine’s complete requirement.
Can I mix API SP and SQ?
Follow the vehicle’s top-up instructions. Do not assume that shared API compatibility makes different viscosities or OEM approvals interchangeable; see mixing engine oils.
Is API SQ the same as ILSAC GF-7?
No. They are related standards with overlapping market use, but the marks and viscosity/application rules are not identical. Read the exact API certification symbols on the product.
Sources
- American Petroleum Institute, Motor Oil Guide, current gasoline categories, licensing dates, category compatibility, API marks, and ILSAC GF-7A/GF-7B guidance. Accessed July 27, 2026.
- American Petroleum Institute, Engine Oil Licensing and Certification System, API certification program and consumer resources. Accessed July 27, 2026.
- SAE International, SAE J300_202405 Engine Oil Viscosity Classification, Scope, viscosity-classification purpose. Revised May 9, 2024; accessed July 27, 2026.
Read Next
- Best Engine Oil: Four Checks That Matter
- OEM Approved vs. “Meets Requirements” Oil
- Synthetic vs. Conventional Engine Oil
| *Last Updated: July 2026 | 6-minute read* |