Standards & Tests

Standards & Tests

SAE J300: How the Viscosity Table Is Built (Without the Math Headache)

Meta Description: Making sense of engine oil viscosity grades is easier than you think—discover how the SAE J300 viscosity table is built without complex calculations.

OilSpec Guide Team
February 9, 2026

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Standards & Tests

ILSAC GF-5 vs GF-6: What Actually Changed?

Perplexed by GF-5 versus GF-6 differences? Discover the key changes and how they impact your engine’s performance and protection.

OilSpec Guide Team
February 9, 2026

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Standards & Tests

ACEA C5 Explained: Why ‘Lower HTHS’ Isn’t Automatically Bad

Skeptical about lower HTHS in ACEA C5 oils? Discover how advanced additives ensure protection and efficiency without compromise.

OilSpec Guide Team
February 8, 2026

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Standards & Tests

ACEA C2 vs C3: The One Number That Usually Decides It

Navigating ACEA C2 versus C3 hinges on one crucial number that influences engine performance, and understanding it is key to making the right choice.

OilSpec Guide Team
February 8, 2026

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Standards & Tests

ACEA A3/B4 Explained: Why It’s Still Everywhere

Discover why ACEA A3/B4 motor oils remain everywhere, offering unmatched engine protection and durability under demanding conditions—find out what keeps them in demand.

OilSpec Guide Team
February 7, 2026

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Standards & Tests

API CK-4 vs FA-4: The Diesel Spec Split Explained Simply

Meta description: “Many diesel engine owners wonder how API CK-4 and FA-4 differ—discover which specification best suits your engine’s needs and why it matters.

OilSpec Guide Team
February 7, 2026

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Standards & Tests

API SP vs SN Plus: The Upgrade Path People Misread

Better oil standards like API SP may seem straightforward, but understanding compatibility is crucial to avoid costly mistakes—find out why.

OilSpec Guide Team
February 6, 2026

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Standards & Tests

Sequence Tests and Real Engines: Why Standards Use Weird Test Names

Learning about sequence test names reveals why standards use peculiar codes—discover the fascinating link between these names and real engine performance.

OilSpec Guide Team
February 5, 2026

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Standards & Tests

NOACK Volatility: The Number That Predicts Oil Consumption (Sometimes)

Greatly understanding NOACK volatility can help predict oil loss, but discovering its limitations is essential for making informed engine oil choices.