The Bilstein B8 Performance Plus is a 46mm monotube gas pressure strut assembly built roughly 0.8 in shorter than the standard damper, so it controls the reduced travel of a car on lowering springs or factory sport suspension. Application specific valving keeps body motion tight without the harshness that comes from running a full length damper on a lowered car, and the monotube layout separates gas from oil so damping stays consistent as the unit heats up. Each strut ships with a fixed spring seat and a blue bellows boot, measures 421mm collapsed and 489mm extended, and is backed by a Bilstein limited lifetime warranty.
Specifications
| Type | B8 Performance Plus monotube strut assembly |
| Position | Front left |
| Damper Design | 46mm monotube, gas pressure |
| Collapsed Length | 421mm (16.57 in) |
| Extended Length | 489mm (19.25 in) |
| Spring Seat | Included, fixed |
| Boot | Blue bellows |
| Finish | Yellow paint |
| Weight | 8.40 lb |
| Country of Origin | Germany |
| Pairs With | Bilstein 35-115946 (front right) |
| Quantity | 1 (two required per axle) |
| Part Number | 35-115939 |
| Warranty | Limited lifetime |
Documents: Installation Instructions (PDF) | Safety Data Sheet (PDF)
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2008-2013 | BMW | 128i | Base |
| 2008-2013 | BMW | 135i | Base |
| 2013 | BMW | 135is | Base |
Shipping
- In-stock orders placed before 3 PM EST ship the same day — everything else ships within 24 hours.
- Standard, expedited, and overnight options at checkout.
- Oversized items ship by freight and take longer.
- Backordered items ship as soon as stock lands — contact us for lead times.
- International orders: prices do not include VAT, duties, or import fees. Your country charges these at import and they are the buyer’s responsibility.
Returns
- 30-day returns on new, uninstalled items in original packaging with all hardware.
- Standard returns: 8% restocking fee, buyer pays return shipping. Both waived if the item is defective or we made the error.
- Installed or used parts can’t be returned — confirm fitment before you install.
- Special orders and custom items are final sale.
- Email us for return authorization before shipping anything back.
Full details: Shipping Policy · Refund Policy
