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Automotive

Royal Purple ROY01021 XPR 5W30 Racing Oil, 1 Quart

Automotive4.7· 716 Amazon ratings

Bias-adjusted across 716 Amazon ratings, Bayesian-shrunk to the category prior so the headline score reflects relative quality — not a raw star average. Cohort: Automotive.

95.5%
Percentile · Global
96.8%
Percentile · Cohort
Automotive
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Royal Purple ROY01021 XPR 5W30 Racing Oil, 1 Quart

How the score was built

Amazon ratings
716

used for the Bayesian percentile

Raw star average
4.7 / 5

unadjusted Amazon mean

Bayesian avg
4.65

raw rating shrunk to the category prior

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Same category · Automotive

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