API SQ is the current API category for gasoline engine oil, introduced in March 2025; API SP is now listed “for 2025 and older automotive engines.” API states that the latest gasoline category “includes the performance properties of each earlier category and can be used to service older engines where earlier category oils were recommended” (API Motor Oil Guide, 2025). So an SQ oil can be used where your manual asks for SP, provided the viscosity and any manufacturer specification also match. 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 | Status in API’s 2025 guide | What API says |
|---|---|---|
| API SP | Current | “For 2025 and older automotive engines.” |
| API SQ | Current, introduced March 2025 | Protection against both fresh and aged oil low-speed pre-ignition (LSPI), improved timing chain wear protection, improved high-temperature deposit protection for pistons and turbochargers, sludge and varnish control |
Source: API Motor Oil Guide (2025-04-21), “Standard for Gasoline Engine Oils” chart.
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 says “API SQ with Resource Conserving matches ILSAC GF-7A,” adding improved fuel economy, emission-control-system protection, low-temperature pumpability and protection for engines running on ethanol blends up to E85 (API guide). The older ILSAC GF-6A and GF-6B standards are marked to become obsolete on October 1, 2026, and API says to use GF-7A where GF-6A is recommended and GF-7B where GF-6B is recommended. 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
Can I use API SQ oil instead of API SP?
Yes, for ordinary gasoline engines. API says the latest category can be used where earlier category oils were recommended, as long as the viscosity and any manufacturer specification in your manual also match.
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, EOLCS Motor Oil Guide (2025-04-21): SQ and SP status and descriptions, backward compatibility statement, SQ/GF-7A relationship, GF-6 obsolescence date. Accessed October 1, 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.
