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The newest generation of engine oil is now in market and owners of heavy-duty vehicles stand ready to reap the benefits. For years, your partners at Phillips 66 have been preparing for this category upgrade with millions of miles of lab and on-road testing. The results? Unprecedented. All of our engineered formulas in the API CK-4 and FA-4 categories exceed standard industry requirements and have proven to maximize fuel economy and wear protection, and minimize emissions.

CK-4 and FA-4 heavy-duty engine oil maximizes fuel economy and wear protection so you can maximize savings and cost efficiency. See how much you can save with our Fuel Savings Calculator.

Phillips 66 Performance for API CK-4 and FA-4
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A snapshot of impressive test results.

Every single test conducted with Phillips 66 products vastly surpassed the API requirements. In addition to reducing emission levels and improving fuel economy, our formulas also provided significant engine protection by decreasing wear, corrosion, and the formation of sludge and grit deposits.

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Corrosion Control

See the engine test results for CK-4

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Wear Protection

See the engine test results for CK-4

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Filter Plugging

See the engine test results for CK-4 and FA-4

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Engine Cleanliness

See the engine test results for CK-4