ST X Coilovers Audi A6 4B 97-06

ST X Coilovers for Audi A6 4B (1997-2006) – 40-75 mm Lower, Height Adjustable, Fixed Damping

This ST X kit replaces the standard springs and dampers on the Audi A6 4B (1997-2006) with a height-adjustable coilover set. It lowers the car by approx. 40-75 mm front and rear, which sharpens the steering, cuts body roll and closes up the wheel arch gap. The ride height is set on threaded struts, so you can go for a subtle drop or use the full approved range, and change it again later.

The ST X is the entry point to the ST range. It is built around a damper setting that ST have matched to this specific car, so there is nothing to adjust beyond ride height. Shaped (progressive) springs keep the ride compliant over small bumps and firm up as the suspension compresses, which makes it a good fit for a daily driver that needs to look lower and feel tighter without becoming harsh. ST is part of the KW automotive group, and the kit is developed and made in Germany using KW engineering.

ST makes 4 versions of the X kit for the Audi A6 4B, split by drivetrain and front axle weight. Between them they cover the 1.8, 1.8 T, 1.9 TDI, 2.0, 2.4, 2.8, 3.0, 2.5 TDI and more. Use the table in the Fitment section to find the right one, then choose it from the drop-down.

Specifications

• Front lowering: approx. 40-75 mm (varies by version)
• Rear lowering: approx. 40-75 mm (varies by version)
• Height adjustment: Stepless, on threaded strut housings
• Minimum ride height (wheel hub centre to arch edge): front 315 mm, rear 320 mm
• Damping: Fixed, pre-set by ST for this vehicle
• Springs: Shaped progressive springs
• Strut housings: Galvanised steel
• Approval: Parts certificate (German §19.3)

Lowering figures are ST's, measured against the standard car. The actual drop varies with engine, equipment and tolerances on each car, and the springs settle slightly after the first few hundred miles.

Key Features

• Stepless ride height adjustment on a coarse, dirt-resistant trapezoidal thread
• Damper setting developed by ST for this vehicle, so no setup is needed beyond ride height
• Shaped progressive springs for a comfortable ride with firmer support in corners
• Galvanised, multi-sealed steel strut housings for long-term corrosion protection
• Composite spring perches with stainless steel inserts that stay easy to adjust for years
• Dust covers and bump stops protect the damper seals and act as an extra spring under heavy load
• Developed and built in Germany, based on KW engineering
• Supplied with a parts certificate and fitting instructions

What's in the Kit?

• 2 x height-adjustable front coilover struts with springs
• Further parts depend on the version: see the Top Mounts and Rear Setup rows in the specification table for each version
• Composite spring perches with stainless steel inserts
• Dust covers and bump stops
• Parts certificate and fitting instructions

Please note: the photos are for reference only and show a typical ST X kit. The exact struts, brackets and springs supplied depend on your car.

Fitment

• Audi A6 4B (Jan 1997 to Dec 2005)
• Audi A6 Avant 4B (Nov 1997 to Jan 2006)

Which version do I need? Find your engine, then match the body style, drivetrain and front axle load. The axle load is on your VIN plate (door pillar or under the bonnet, the line marked "1-"). Not sure? Send us your registration and we will check.

Not suitable for: Other generations or body styles, which need their own kit, such as ST X Coilovers Audi A6 4F 04-11, ST X Coilovers Audi A6 4G/4G1 11-19.

Installation

Fitting means removing the original struts, springs and dampers and fitting the ST units in their place. We recommend a qualified workshop experienced with coilovers. A spring compressor is needed to strip down the original front struts. The original top mounts, bearings and fixings are reused, so check them for wear and replace any that are worn. Set the ride height within the approved range, tighten the suspension bolts with the car's weight on its wheels, and torque everything to the manufacturer's figures. A four-wheel alignment is required once the car is at its final ride height. Re-check the height and alignment after the first few hundred miles, once the springs have settled.

The fitting instructions and parts certificate for each version can be downloaded from its specification table once you choose your version.

Before you start:

• Where no bump stop is supplied, the original bump stops are reused, so replace any that are worn or damaged.
• Disconnect any ride height sensors (headlight levelling or self-levelling) before removing the old struts.
• Clean the threads before adjusting, and start with the height adjusters in the middle of their range.

After fitting:

• Do not go below ST's minimum height, measured from the wheel hub centre to the wheel arch edge: front 315 mm, rear 320 mm.
• Expect the car to settle a further 5-10 mm once it has been driven, then re-check the height.
• Check there is at least 5 mm clearance between the tyres and the suspension through the full steering and suspension travel.
• Have the headlight aim reset, along with any other height-dependent systems.
• ESP/ABS warning lights can appear after fitting. Some clear after a short drive, others need full steering lock both ways or a reset with a diagnostic tool.
• On cars with radar or camera driver assistance systems, have the calibration checked after lowering.

Upgrade Further

Want to fine-tune the ride? The ST XA Coilovers Audi A6 4B 97-06 adds 16-click rebound adjustment.

Which version do I need for my Audi A6 4B?

Start with your engine in the Fitment table, then match the body style, drivetrain and front axle load (on your VIN plate). If more than one row fits, or your car isn't listed, send us your registration and we will confirm the right part number.

Will this fit my Audi A6 4B?

It fits the Audi A6 4B (1997-2006) with the 1.8, 1.8 T, 1.9 TDI, 2.0, 2.4, 2.8 and more. Check the Fitment section for the body styles and exclusions, or send us your registration and we will check.

How low will my Audi A6 4B sit?

ST quotes a drop of approx. 40-75 mm front and rear compared with standard, depending on the version. The exact drop varies from car to car with engine, equipment and tolerances. ST also sets a minimum: the distance from the wheel hub centre to the wheel arch edge must stay above approx. 315 mm at the front and 320 mm at the rear.

Can I adjust the damping?

No, the damping is pre-set by ST to suit the springs, so there is nothing to set up. You only adjust the ride height. If you want adjustable damping, look at the ST XA.

Will the ST X make my Audi A6 4B ride harshly?

The ST X uses progressive springs and a fixed damper setting chosen by ST for this car, so it is firmer than standard but still suits everyday driving. Lowering a long way or fitting low-profile tyres will firm up the ride more than the coilovers themselves.

Do I need an alignment after fitting?

Yes. Changing the ride height changes camber and toe, so a full four-wheel alignment is needed once the car is at its final height, and again after any later change.

Is it road legal in the UK?

Yes. It is designed for road use and comes with a German parts certificate. Keep the ride height within ST's approved range and tell your insurer about the modification.

What is the difference between ST and KW coilovers?

ST is part of the KW group and its coilovers are made in Germany using KW engineering. ST uses galvanised steel strut housings and offers fewer adjustment options than KW's stainless steel Variant range, which keeps the price lower.

Is it covered by a warranty?

Yes, ST covers it against defects in materials and workmanship. If a part ever needs replacing, contact us with your vehicle details and order number.