4pcs Car Pistons And Rings Kit 84mm Φ22mm CR 10:1 11257640166 11258606459 for 328i 428i 528i X3 F30 F10 2.0T N20B20A Engine This piston and ring kit includes four pistons with corresponding rings designed for engine rebuilds.Each piston has a diameter of 84mm and a pin bore of Φ22mm, with a compression ratio of 10:1.The set is compatible with specific engine models requiring part numbers 11257640166 and 11258606459.Components are -engineered to meet specifications for proper fit and function.Intended for use in 2.0L turbocharged engines found in certain vehicle platforms.This kit supports complete cylinder replacement during major engine maintenance or performance. Compatibility Notice: This is an aftermarket product.Mention of brands is for fitment identification only.