Bilstein 46-190321 B12 Pro-Kit Lowering Suspension for 2003-2009 Mazda 3 BK 2.3L

Vehicle Fitment

• 2003-2009 Mazda 3 Hatchback (BK, FWD, 2.3L I4)
• 2004-2009 Mazda 3 Sedan (BK, FWD, 2.3L I4)
• 2007-2009 Mazda Mazdaspeed3 (BK14, FWD, 2.3L Turbo I4)

Fitment Notes

• Fits BK platform Mazda 3 models only (1st generation)
• Designed for vehicles equipped with 2.3L engines only
• Does not fit AWD models or later BL (2010+) chassis
• Lowering amount varies slightly between standard and Mazdaspeed trims

Features

• Complete matched suspension system with shocks and lowering springs
• Includes Bilstein B8 Performance Plus dampers
• Paired with Eibach Pro-Kit progressive lowering springs
• Mono-tube gas pressure technology for consistent damping performance
• Improves handling, cornering stability, and steering response
• Reduces body roll and squat under acceleration
• Optimized damping rates matched specifically to spring characteristics
• Maintains daily drivability with sport-tuned comfort balance
• Corrosion-resistant construction for long service life

Specifications

• Product Type: Suspension Kit (Shocks + Springs)
• Series: Bilstein B12 Pro-Kit
• Shock Type: Mono-tube, gas pressure
• Lowering Amount (Front): approx. 25 mm (≈1.0 in)
• Lowering Amount (Rear): approx. 15 mm (≈0.6 in)
• Alternative Range: approx. 24-40 mm depending on model
• Axle Load Rating (Front): up to 1070 kg
• Axle Load Rating (Rear): up to 915 kg
• Position: Front and Rear

Included Components

• 2x Front Bilstein B8 Performance Plus Struts
• 2x Rear Bilstein B8 Performance Plus Shocks
• 2x Front Eibach Pro-Kit Lowering Springs
• 2x Rear Eibach Pro-Kit Lowering Springs

Product Description

The Bilstein 46-190321 B12 Pro-Kit is a complete performance suspension upgrade engineered specifically for the first-generation Mazda 3 platform. This kit combines Bilstein's high-performance B8 dampers with Eibach's precision-tuned Pro-Kit lowering springs, delivering a balanced solution for drivers seeking improved handling without sacrificing everyday usability. The system is designed as a matched set, ensuring optimal interaction between spring rates and damping forces for predictable, responsive performance.

With a moderate lowering profile, this kit enhances vehicle stance while reducing body roll, brake dive, and acceleration squat. The mono-tube gas pressure dampers provide consistent performance under load and heat, making it ideal for spirited street driving. Whether installed on a standard Mazda 3 or Mazdaspeed3, the B12 Pro-Kit delivers sharper handling, improved stability, and a more connected driving experience while retaining ride comfort suitable for daily driving.