Audi B9 S4/S5/RS5 Coilovers: Ohlins vs Bilstein vs KW

The best Audi B9 S4/S5/RS5 coilovers for most drivers are the Öhlins Road & Track system, which pairs Dual Flow Valve (DFV) monotube dampers with independent ride-height and 30-click damping adjustment for a track-capable setup that still behaves on the street. But the right suspension for your 2017-2020 Audi B9 depends on one key question: do you want to keep the factory adaptive dampers, or replace them entirely? This comparison breaks down four proven upgrades — from a full Öhlins coilover to a set of H&R sport springs — across drop range, damping adjustment, electronic-damper compatibility, and price (roughly the $416 to $3,300 range).

Why upgrade the B9 S4/S5/RS5 suspension?

The B9-chassis Audi S4, S5 and RS5 leave the factory tuned for daily comfort, and that softness shows up as body roll, nose dive under braking, and a ride height with obvious wheel gap. Upgrading the suspension on your 2017-2020 Audi B9 sharpens turn-in, plants the quattro AWD system under power, and drops the car 15-50 mm (roughly 0.6-2.0 in) for a purposeful stance. The S4 and S5 run a 349-hp 3.0T turbocharged V6, while the RS5 steps up to a 444-hp 2.9T twin-turbo V6 — both put roughly 3,800-4,000 lb on the tires, so springs and dampers matched to that mass make a measurable difference in grip and confidence.

The biggest decision on a B9 is whether your car has factory adaptive dampers. S sport suspension (with damper control) and the RS sport suspension with Dynamic Ride Control (DRC) change how much of the OEM system you keep. Some upgrades replace the dampers outright; others are engineered to retain the electronic damping and the dashboard comfort/sport selector. Choosing wrong means either a dashboard warning light or leaving money on the table.

Coilovers vs height-adjustable springs vs lowering springs

There are three ways to lower and firm up a B9 Audi, and they sit at very different price points. A coilover replaces the spring and damper as one adjustable assembly, giving you independent control of ride height and (on the Öhlins) damping stiffness — the most capable but the most expensive route. A height-adjustable spring (H.A.S.) kit, like KW's, reuses your factory dampers and adds threaded, adjustable perches so you can dial in ride height while keeping the OEM adaptive damping and ride quality. Lowering springs, such as H&R Sport Springs, are a fixed-drop progressive spring that bolts onto the factory struts — the simplest, most affordable stance-and-handling upgrade.

In short: coilovers are for the driver who wants maximum adjustability and track pace; H.A.S. kits are for owners who love their adaptive dampers but want a lower, tighter car; and lowering springs are the budget-friendly gateway that keeps everything else stock.

Ohlins Road & Track (B9): the track-day benchmark

The Öhlins Road & Track system is the most capable coilover for the B9 S4/S5/RS5, built around aluminum monotube dampers and Öhlins' patented Dual Flow Valve (DFV) technology. DFV adds a second oil-flow path that opens on low-speed inputs (body roll, dive, squat) and closes under sharp high-speed hits, so the damper stays firm in cornering yet still soaks up a broken expansion joint. A single 30-click golden knob at each corner simultaneously adjusts low- and high-speed compression and rebound, and ride height is set on the threaded body independent of spring preload — so you can change stance without corrupting spring load. Spring rates are a purposeful 120/140 N/mm front/rear.

Bilstein B16 DampTronic: keep the comfort/sport button

The Bilstein B16 DampTronic is the coilover for B9 owners who love their factory electronic dampers. Unlike a conventional coilover, the B16 DampTronic retains the OEM adaptive damping system — the comfort and sport modes and the dashboard selector all keep working, with no fault codes. You get Bilstein's zinc-coated, threaded monotube bodies for adjustable ride height (roughly 5-50 mm, about 0.2-2.0 in, depending on axle) while the car still softens itself in Comfort for the daily commute and firms up in Dynamic for a canyon run. At around $2,499 (down from an MSRP near $3,611), it splits the difference between a fixed coilover and the Öhlins.

KW Height Adjustable Springs (H.A.S.): stance without losing EDC

KW's Height Adjustable Spring (H.A.S.) kit is the smartest choice for a B9 owner who wants a lower, tighter car but refuses to give up the factory Electronic Damping Control (EDC). Instead of replacing the dampers, the H.A.S. kit installs stainless-steel, threaded lower spring perches on the OEM struts, letting you dial in a continuously adjustable drop of roughly 15-45 mm (about 0.6-1.8 in) front and rear. Because the factory dampers and EDC stay in place, the adaptive ride quality and dashboard modes are fully preserved — you simply get a lower center of gravity and reduced wheel gap. It is TUV-tested KW hardware at around $1,284, roughly a third the price of the Öhlins.

H&R Sport Springs: the budget stance upgrade

H&R Sport Springs are the most affordable way to lower a B9 Audi, and for the RS5 they are engineered to work with the factory RS suspension and Dynamic Ride Control (DRC). These progressive-rate springs bolt onto your OEM dampers and deliver a modest, DRC-friendly drop of roughly 15-20 mm (about 0.6-0.8 in) — enough to close the wheel gap and lower the center of gravity without the harshness of an aggressive slam. Progressive rates mean a compliant initial stroke for daily comfort that firms up as the spring compresses in hard cornering. At around $416 (MSRP near $489) with an H&R limited lifetime warranty, it is the classic gateway modification.

How to choose the right B9 suspension for you

Choose your B9 suspension by matching the upgrade to how you actually drive. For serious canyon and track use where you want to fine-tune the car, the Öhlins Road & Track coilover is the clear answer — just budget for the cancellation kit if your S4/S5/RS5 has adaptive dampers. If you commute daily and love the factory comfort/sport button, the Bilstein B16 DampTronic gives you adjustable ride height while keeping every electronic feature. If your priority is a lower, cleaner stance with zero compromise to the OEM adaptive ride, KW's H.A.S. kit is the sweet spot. And if you want the biggest visual and handling improvement per dollar, H&R Sport Springs deliver.

One caution specific to the B9: verify whether your car has the standard passive suspension, S sport suspension with damper control, or the RS sport suspension with DRC before you order. The Bilstein DampTronic and KW EDC kits are engineered around the electronic-damper cars, while a full Öhlins coilover replaces those dampers entirely and needs the matching Öhlins cancellation harness to prevent a dashboard fault.

Installation and alignment notes

Plan on a professional install and a four-wheel alignment for any B9 suspension upgrade. At our Tampa, FL shop, a full coilover install on an S4/S5/RS5 typically runs 4-6 hours including corner-balancing and setting ride height, while lowering springs take roughly 2-3 hours. Lowering a quattro Audi meaningfully changes camber and toe, so a corner-balanced setup and a fresh alignment are not optional if you want even tire wear and predictable handling. Budget for an alignment after the car has settled a few hundred miles, and re-torque hardware at the first service interval. If you are keeping factory adaptive dampers, confirm you ordered the correct EDC/DRC-compatible part number for your exact trim.