Ford Performance announced a tune for the four-cylinder-powered Bronco that unlocks more power and reportedly improves drivability. Only compatible with premium gasoline, the Performance Calibration kit was developed in-house, so it doesn’t void the factory warranty.

Stock, the Bronco’s turbocharged, 2.3-liter EcoBoost four-cylinder engine develops 300 horsepower and 325 pound-feet of torque when it’s burning 93-octane gasoline. Ford’s tune increases those figures to 330 and 385, respectively. For context, the 2.7-liter twin-turbocharged V6 develops up to 330 horsepower and 415 pound-feet of torque. Ford notes the tune also improves throttle response throughout the rev range.

Beyond the engine, the tune also has an effect on the transmission. It optimizes the shift schedule in Bronco models equipped with the 10-speed automatic, and it adds a rev-matching function that kicks in when downshifting to SUVs fitted with the seven-speed manual. Owners who buy the tune can fit 37×12.5R17 BFGoodrich KO2 tires (the same ones installed on the Bronco Raptor) and an axle ratio of up to 4.70.

On sale now, the Performance Calibration kit costs $825 excluding installation, and it’s covered by a three-year, 36,000-mile warranty plan that starts on the vehicle’s in-service date. There’s a catch: The kit hasn’t been approved by regulators in California for 2022 Bronco models, so Golden State residents will need to find a 2021 truck or settle for the EcoBoost’s stock output. It’s street-legal in the rest of the nation.

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