Product Details
BC Racing ER Series Coilovers for the 1999-2004 Audi A6 (C5) put race-grade adjustability in reach of the serious track-day driver, with independent compression and rebound tuning at every corner. Every kit is extensively tested on the A6 C5 chassis and refined until it balances ride quality with performance — the reason A6 coilovers from BC Racing are the best-selling adjustable kits in their segment worldwide.
ER Series kits run a linear twin-piston design in a mono-tube body, with compression and rebound on separate external adjusters. That lets you fine-tune chassis balance corner by corner — stiffer front for turn-in, softer rear for exit grip, whatever the session calls for. BC Racing takes pride in choosing spring rates and damper valving that balance comfort and performance — you never end up with the oversprung, harsh-riding kit some brands ship as their only option. Drivers who want to deviate from the factory setup can order Swift Springs, custom spring rates, and custom valving at checkout; BC will re-valve the dampers to match whatever you specify, a level of customization most brands reserve for their top-tier race kits.
Since 2004, BC Racing has grown into one of the most trusted names in aftermarket coilovers — not by racing to the bottom on price, but by pairing that price with real build quality, deep customization options, and a damper design any suspension shop can rebuild instead of replacing. These A6 coilovers arrive tuned for the C5 chassis and ready to bolt in — no break-in period, no guessing at setup. Every kit ships with a 2-year manufacturer warranty, lifetime access to BC service parts (pistons, seals, shafts — no unit replacement required when it's time for a rebuild), and in-house tech support from both BC Racing and the Springrates team.
Features
- 30-level rebound adjustment (top of damper)
- 30-level compression adjustment (external reservoir)
- Mono-tube damper with linear twin-piston design
- Ride height adjustable independent of spring preload
- Upper mount hardware varies by chassis — camber plates, pillowball, or reused OEM mounts. See the Specifications table for what's included on your kit.
- Swift Spring and custom spring rate upgrades available at checkout
- Custom damper valving paired with custom spring rates on request
- Fully rebuildable — replacement parts available from BC for the life of the shock
- 2-year manufacturer warranty against defects
Specifications
| Part Number | S-12-ER |
| Part Name | ER Series Coilovers |
| Vehicle | 1999-2004 Audi A6 AWD (C5) |
| Drivetrain | AWD |
| Chassis Code | C5 |
| Damping Adjustment | 2-Way (30 levels rebound / 30 levels compression) |
| Ride-Height Adjustable | Yes |
| Spring Rate - Front | 14 kg/mm |
| Spring Rate - Rear | 8 kg/mm |
| Spring Size - Front | 62-200-14K |
| Spring Size - Rear | 62-200-8K |
| Swift Springs - Front | 62-178-X |
| Swift Springs - Rear | 62-178-X |
| Camber Plates - Front | Not Applicable |
| Camber Plates - Rear | Not Applicable |
| Suspension Design - Front | True Coilover |
| Suspension Design - Rear | True Coilover |
| Notes | The ER Series is not available in Extreme-Low configuration. |
Vehicle Fitment
- 1999 Audi A6 AWD (C5)
- 2000 Audi A6 AWD (C5)
- 2001 Audi A6 AWD (C5)
- 2002 Audi A6 AWD (C5)
- 2003 Audi A6 AWD (C5)
- 2004 Audi A6 AWD (C5)