AST ASTLS-21-043 Lowering Springs for 21-24 BMW G22 4 Series M440i xDrive Coupe

Vehicle Fitment

• 2021+ BMW M440i xDrive Coupe (G22, B58 3.0L TwinPower Turbo I6 + 48V mild hybrid, 382hp, xDrive AWD, 8-speed automatic)

Fitment Notes

• AST's confirmed production window for this application starts at 09/2021, covering the second-generation BMW 4 Series (G22) M440i xDrive Coupe. The M440i xDrive is exclusively an all-wheel drive model in all markets globally - there is no rear-wheel-drive M440i, making this a dedicated AWD application across all M440i Coupe sales worldwide.
• This fitment is confirmed for the G22 Coupe (two-door) body style only. The G23 M440i Convertible and G26 M440i xDrive Gran Coupe are separate body styles with different body mass and rear structure - they are not confirmed fitments for this part number. Confirm with AST before ordering for Convertible or Gran Coupe body styles.
• The G22 M440i xDrive is equipped with a 48-volt mild hybrid system integrating a starter-generator motor with the B58 engine. The 30mm/30mm drop calibration accounts for this hybrid system's additional front-end mass. The spring kit does not interact with or affect the mild hybrid system or its associated electronics.
• The vast majority of G22 M440i xDrive deliveries include the M Sport suspension package as standard or near-standard specification, which features factory-tuned (and in some markets, slightly lowered) springs. The indicated 30mm front / 30mm rear drop is measured from the M440i's standard factory ride height. On markets or configurations where the M Sport suspension includes a factory lower ride height, the effective drop may be modestly reduced relative to the stated figures.
• G22 M440i xDrive models optionally equipped with Adaptive M Suspension (EDC / electronically controlled dampers): EDC compatibility for this fixed spring kit has not been explicitly confirmed in available AST documentation. If your vehicle has the Adaptive M Suspension option, confirm compatibility directly with AST before ordering. A separate AST Adjustable Lowering Spring (ALS) kit (ASTALS-21-003) is available for the G22 M440i xDrive and is confirmed EDC compatible.
• The G22 4 Series LCI facelift began production in early 2024 with styling updates. If your G22 was built from 2024 onward (LCI), verify with AST that the spring perch geometry is unchanged before ordering.
• Front drop: 30mm / Rear drop: 30mm. These are fixed values - this is not an adjustable spring kit.
• Wheel alignment must be verified and corrected following installation. ABS sensor positions should be re-adjusted post-installation.

Features

• M440i xDrive-specific progressive spring rate, developed and validated by AST engineers for the G22 M440i's xDrive all-wheel drive platform - accounting for the B58 engine's mass, the 48V mild hybrid system's additional front-end weight, and the AWD drivetrain's front axle load contributions.
• Uniform 30mm front and rear drop - calibrated for the G22's near 50/50 weight distribution and MacPherson strut front / multi-link rear suspension geometry, producing a level, balanced lowered stance without inducing adverse suspension geometry changes at either axle.
• Lowers the M440i's center of gravity at both axles, reducing body roll, sharpening initial turn-in response, and enhancing the cornering composure of a platform that already features BMW's Adaptive M chassis tuning and xDrive torque distribution.
• Progressive spring design delivers improved body motion control at spirited pace while retaining appropriate ride compliance for grand touring use - consistent with the M440i's positioning as a high-performance daily sports coupe rather than a track-only vehicle.
• Direct OEM spring replacement - installs into the factory front MacPherson strut housings and rear multi-link spring perches using original mounting hardware; no modification to the xDrive system, mild hybrid components, or suspension geometry required.
• Developed and tested to work correctly with the standard factory shock absorbers and struts, allowing spring-only installation without requiring concurrent damper replacement.
• Manufactured from premium high-tensile chromium-silicon wire, individually handpicked by AST engineers for material quality and long-term fatigue resistance.
• Cold-wound on precision Wafios coiling machines, then heat-treated to increase hardness and eliminate residual winding stress from the manufacturing process.
• Each spring is individually shot peened, phosphate treated, and powder coated for maximum corrosion resistance and long-term service life.
• Each spring is blocked and computer-tested prior to shipment to minimise post-installation settling, so the 30mm/30mm target drop is achieved immediately upon installation.
• Most AST spring applications are TUV certified - certificates available upon request for technical inspection or registration compliance.
• Lifetime warranty against breakage - backed by AST Suspension's manufacturer guarantee.

Specifications

• Part Number: ASTLS-21-043
• Type: Fixed Lowering Springs (full set of 4)
• Spring Design: Progressive rate
• Spring Material: Premium high-tensile chromium-silicon wire
• Manufacturing Process: Cold-wound, heat-treated, shot peened, phosphate treated, powder coated, computer-tested
• Front Lowering: 30mm
• Rear Lowering: 30mm
• Engine: B58 3.0L TwinPower Turbo I6 + 48V mild hybrid (382hp / 500 Nm)
• Front Suspension Type: MacPherson strut (with xDrive front axle)
• Rear Suspension Type: Multi-link independent
• Drivetrain: xDrive AWD only (M440i is exclusively AWD in all markets)
• Body Style: G22 Coupe (two-door) confirmed - G23 Convertible and G26 Gran Coupe not confirmed for this part number
• Transmission: 8-speed automatic (only transmission offered with M440i)
• Fitment Style: Direct OEM spring replacement
• Warranty: Lifetime against breakage
• TUV Certification: Available upon request
• Position: Front Left, Front Right, Rear Left, Rear Right

Included Components

• 2x Front lowering springs (left and right)
• 2x Rear lowering springs (left and right)

Product Description

The AST ASTLS-21-043 Lowering Spring Kit is designed for the second-generation BMW 4 Series M440i xDrive Coupe (G22), covering production from September 2021 onward. The M440i xDrive is unique within the G22 range in that xDrive is the only drivetrain offered - there is no rear-wheel-drive M440i. This means the ASTLS-21-043 is a fully universal fit for every G22 M440i Coupe delivered globally, with no need to distinguish between AWD and RWD variants. The 30mm front and rear drop is calibrated for the G22 M440i's specific weight distribution, which reflects both the B58 engine's substantial mass and the additional front-end weight of the 48-volt mild hybrid integrated starter-generator - a system that adds modest but real mass to the front of the car compared to a conventional combustion-only powertrain.

The uniform 30mm drop front and rear suits the G22's near-50/50 weight distribution well, producing a level stance and equal improvements in centre-of-gravity height at both ends of the car. On the G22's MacPherson strut front and multi-link rear suspension, this amount of lowering sits comfortably within the range where standard four-wheel alignment correction restores all suspension geometry values to their optimal settings. The practical outcome is a meaningfully improved chassis character: reduced body roll during cornering, a sharper and more direct initial turn-in feel, and a more committed, grounded presence on the road - all without compromising the everyday compliance and refinement that define the M440i's grand touring character.

Owners who prefer an adjustable drop or who have the Adaptive M Suspension (EDC) option fitted and want confirmed electronic compatibility should consider the AST Adjustable Lowering Spring kit (ASTALS-21-003), which covers the G22 M440i xDrive with a variable drop range and confirmed EDC compatibility. For fixed-drop installations without EDC, the ASTLS-21-043 provides a proven, straightforward direct-replacement solution. Every spring is manufactured from premium chromium-silicon wire on Wafios coiling machines in the Netherlands, individually computer-load tested before shipment, and backed by AST's lifetime warranty against breakage. TUV certification documentation is available on request.