This document provides an overview of API engine oil classifications and specifications for service fill oils used in gasoline, light-duty diesel, and heavy-duty diesel engines. It includes:
1. API specifications and classifications for engine oils, including requirements and test methods for various performance tests in the lab and engine tests.
2. Tables listing specific test properties, test methods, and limits for different API categories including SN-RC/GF-5 for passenger cars, CH-4 for heavy-duty diesels, and SM for passenger cars.
3. Footnotes providing additional details on test requirements and limits for some API categories.