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Commonly BSFC is expressed in units of grams per kilowatt-hour (g/(kW·h))."- Wikipedia
Hybrid Assistant shows BSFC in the Engine Power Meter using a color scale reflecting efficiency:
Cyan - Best efficiency range (220 g/kWh)
Yellow - High efficiency range (230 g/kWh)
Orange - Medium efficiency range (240 g/kWh)
Red - Low efficiency range (> 240 g/kWh)
Actual thresholds vary with engine type, according to official Toyota documents