{
  "name": "Motor oil glossary",
  "attribution": "Oil Manual (oilmanual.com) — CC BY 4.0",
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "source": "https://oilmanual.com/glossary/",
  "documentation": "https://oilmanual.com/datasets/",
  "language": "en",
  "terms": [
    {
      "term": "Viscosity",
      "definition": "How thick an oil is and how easily it flows. Lower viscosity = thinner; higher = thicker.",
      "url": "https://oilmanual.com/learn/what-is-oil-viscosity/"
    },
    {
      "term": "SAE J300 grade",
      "definition": "The industry standard that classifies oils by cold-flow (the W number) and hot viscosity (the second number), e.g. 5W-30.",
      "url": "https://oilmanual.com/learn/sae-oil-grades-explained/"
    },
    {
      "term": "W (Winter) rating",
      "definition": "The number before the W. It rates how easily the oil flows when cold — a lower number flows better on cold starts.",
      "url": "https://oilmanual.com/learn/what-is-oil-viscosity/"
    },
    {
      "term": "Multigrade oil",
      "definition": "An oil that meets a cold-flow rating and a hot-viscosity rating at once (e.g. 5W-30), so it works across a wide temperature range.",
      "url": "https://oilmanual.com/learn/oil-viscosity-and-temperature/"
    },
    {
      "term": "Specification (oil spec)",
      "definition": "A performance standard the oil must meet (API, ILSAC, ACEA, or an OEM approval) — separate from the viscosity grade. Match both.",
      "url": "https://oilmanual.com/learn/api-sp-vs-ilsac-gf-6/"
    },
    {
      "term": "API service category",
      "definition": "American Petroleum Institute gasoline-oil category, such as API SQ today or API SP in many recent manuals.",
      "url": "https://oilmanual.com/standards/api-sq-ilsac-gf-7/"
    },
    {
      "term": "API SQ",
      "definition": "The current API gasoline-engine oil service category introduced with the ILSAC GF-7 family. Match it only where the manual or approved replacement path supports it.",
      "url": "https://oilmanual.com/standards/api-sq-ilsac-gf-7/"
    },
    {
      "term": "ILSAC",
      "definition": "Fuel-economy oil standards used alongside API categories, including GF-7A / GF-7B today and GF-6A / GF-6B in many recent manuals.",
      "url": "https://oilmanual.com/standards/api-sq-ilsac-gf-7/"
    },
    {
      "term": "ILSAC GF-7",
      "definition": "The newer ILSAC gasoline-oil family: GF-7A uses the Starburst branch, while GF-7B is the separate 0W-16 Shield branch.",
      "url": "https://oilmanual.com/standards/api-sq-ilsac-gf-7/"
    },
    {
      "term": "ACEA sequences",
      "definition": "European oil classes (A/B, C, E) covering gasoline, diesel, low-SAPS and heavy-duty needs.",
      "url": "https://oilmanual.com/standards/acea-oil-sequences/"
    },
    {
      "term": "dexos",
      "definition": "General Motors’ oil specifications (e.g. dexos1 Gen3 for gasoline) layered on top of API/ILSAC.",
      "url": "https://oilmanual.com/standards/dexos1-gen3/"
    },
    {
      "term": "LSPI",
      "definition": "Low-speed pre-ignition — abnormal combustion mainly in turbo direct-injection engines; modern specs test against it.",
      "url": "https://oilmanual.com/learn/what-is-lspi/"
    },
    {
      "term": "HTHS viscosity",
      "definition": "High-temperature high-shear viscosity — how the oil protects under heat and load. Lower HTHS aids economy.",
      "url": "https://oilmanual.com/learn/what-is-hths-viscosity/"
    },
    {
      "term": "Base oil group",
      "definition": "API classification of base oils (Groups I–V). Synthetic oils use higher groups; it affects quality and the spec, not the grade.",
      "url": "https://oilmanual.com/learn/base-oil-groups-explained/"
    },
    {
      "term": "Additive package",
      "definition": "Detergents, dispersants, anti-wear (e.g. ZDDP), viscosity modifiers and antioxidants blended into the base oil.",
      "url": "https://oilmanual.com/learn/oil-additives-explained/"
    },
    {
      "term": "Synthetic vs conventional",
      "definition": "Synthetic oils are engineered for better cold flow and stability; conventional is mineral-based. Either must still meet your spec/grade.",
      "url": "https://oilmanual.com/learn/synthetic-vs-conventional-oil/"
    },
    {
      "term": "Oil change interval",
      "definition": "How often to change the oil — set by your manufacturer for your engine and driving conditions, not by a shop sticker.",
      "url": "https://oilmanual.com/guides/oil-change-interval/"
    },
    {
      "term": "Severe service",
      "definition": "Tougher driving (short trips, heat/cold, towing, dust, idling) that usually calls for a shorter oil-change interval.",
      "url": "https://oilmanual.com/guides/severe-service-oil-changes/"
    },
    {
      "term": "Oil capacity",
      "definition": "How much oil the engine holds (with filter), in quarts or liters — specific to the year/make/model/engine."
    }
  ]
}