Which tire has the highest Treadwear (UTQG) in size 255/60R15

It's time to buy new tires for my car, but I want to buy a tire that lasts longer than the original brand, OEM. Which tire has the highest Treadwear in this size 255/60R15?

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500 - Treadwear

 Hankook Dynapro HP RA23 - UTQG: 500AA - Tire Rating: 4.17

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440 - Treadwear

 Dunlop SP Sport GT - UTQG: 440AA - Tire Rating: 4.25

 Cooper Cobra Radial G/T - UTQG: 440AB - Tire Rating: 4.43

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420 - Treadwear

 Kumho Ecsta STX KL12 - UTQG: 420AA - Tire Rating: 4.5

 Marshal Matrac STX KL12 - UTQG: 420AA - Tire Rating: 4.66

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400 - Treadwear

 Pirelli Scorpion Zero - UTQG: 400AA - Tire Rating: 3.53

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