Bilstein sorts its shocks into product lines with a letter and a number: B4, B6, B8, plus B12 for springs and kits and B1 for components. On a passenger car the lines step from factory ride to sport. On trucks, motorhomes and vans the same letters show up with four-digit names like 4600 and 5100, and the meaning shifts a little. This guide explains what each line is for in Bilstein's own words and how that maps to the parts in our Bilstein collection.
The lines in one table
| Line | What Bilstein says it is | Ride height | Examples we carry |
|---|---|---|---|
| B4 | The OE replacement shock, built to the original part's specification and function, in monotube or twin-tube form to suit the vehicle | Factory | Sprinter, Transit and ProMaster vans |
| B6 | The bolt-on performance upgrade for a stock suspension, tuned firmer than OE, on the existing springs | Factory | Motorhome chassis, E-Series, Express/Savana, vans |
| B6 4600 | The truck and SUV B6: "performance upgrade for stock ride-height applications" | Factory | Tacoma, Tundra, 4Runner, F-250, Ram 2500, Silverado HD |
| B6 Camper / B6 Camper Advanced | B6 tuned for camper vans and their extra weight; Advanced adds DampMatic | Factory | Mercedes and Freightliner Sprinter |
| B8 (cars) | The sport shock for lowered cars, shortened to suit lowering springs | Lowered | Not stocked |
| B8 5100, 5160, 6100, 6112, 8100, 8112 (trucks) | Bilstein's truck and SUV upgrades for leveled and lifted applications | Leveled or lifted | Tow trucks and overland rigs |
| B12 | Bilstein springs (listed as B12 Special in our catalog) | Varies by part | Toyota and Lexus lift and heavy-load springs |
| B1 | Components and accessories | n/a | F-53 steering stabilizer bracket kit |
B4: put the original ride back
Bilstein describes the B4 as its OE replacement shock: built to match the original part's specification and function, made to OE standards, and in monotube or twin-tube form to suit the vehicle. On its US store, Bilstein's B4 van parts carry the line that they are for "maintaining the original ride quality of your vehicle."
Choose B4 when the van rode the way you liked from the factory and the shocks are simply worn. In our catalog, B4 parts cover the Mercedes Sprinter 3500, the Ford Transit and the Ram ProMaster, among others.
B6: firmer than stock, same height
Bilstein calls the B6 the bolt-on performance upgrade for a stock suspension, tuned firmer than OE, which sharpens control on your existing springs at the original ride height. Bilstein lists coverage from cars to SUVs, vans, classics and campers.
For motorhomes, B6 is the line you will see on almost every chassis part. Bilstein's US store lists the F-53 front shock 24-234511 as a B6 for a Class A chassis, and the E-Series Comfort pair as B6 parts for a Class C. Bilstein's description for these motorhome B6 shocks: a monotube design with a velocity-sensitive digressive piston, tuned for each specific application.
One detail worth knowing: Bilstein's general B6 page shows the classic yellow monotube, but its van struts are not all monotube. Bilstein's own spec sheet lists the Transit B6 front strut 22-249357 as twin-tube with a black finish. Read the spec on the part, not the line name.
B6 4600: the truck version
For pickups and SUVs Bilstein brands the stock-height B6 as the B6 4600. Bilstein's US off-road site calls it a "performance upgrade for stock ride-height applications," with a 46mm monotube, digressive valving and no spring change required. If your truck is at factory height, this is the line.
B6 Camper and B6 Camper Advanced
Bilstein's US store describes the B6 Camper as tuned for each application and for the increased vehicle weight of a camper van. The B6 Camper Advanced adds Bilstein's patented DampMatic technology, which Bilstein's camper site says switches between two damping curves mechanically, without a solenoid valve. We carry both for Sprinter vans; see Bilstein shocks for Sprinter, Transit and ProMaster vans.
B8: where cars and trucks part ways
On a car, Bilstein's B8 is the sport shock for lowered cars: shortened by design so the shock keeps proper preload and travel on lowering springs. We don't sell car B8s.
On trucks, the B8 prefix belongs to Bilstein's leveled and lifted range. Bilstein's US off-road site lists:
- B8 5100: "performance upgrade for lifted applications," made in various lift heights.
- B8 5100 (Ride Height Adjustable): "leveling shocks for OE coilover applications," with 0 to 2.75 in of adjustment depending on the vehicle.
- B8 5160: the 5100's monotube with a remote reservoir, for lifted trucks, Jeeps and SUVs.
- B8 6112: a 60mm coilover kit with its own springs and adjustable seats; Bilstein's page describes the front kit, and the Bronco also has rear kits.
- B8 8100 and 8112: 60mm reservoir shocks and coilovers for lifted trucks and SUVs.
So "B6 or B8" on a truck is really "stock height or lifted." Our 4600 vs 5100 guide covers that choice, and choosing Bilstein shocks by lift height covers how to read the lift ranges.
B12 and B1
B12 parts in our catalog are Bilstein springs, for example the Lexus GX460 rear coil springs 36-281817, which Bilstein lists for 1 in of rear lift on the GX460. B1 is Bilstein's components line; the one most motorhome owners meet is the F-53 stabilizer bracket kit 11-317555, which Bilstein lists for chassis without factory stabilizer mounts.
Which line should you buy?
- Van or motorhome, happy with the factory ride, shocks worn out: B4 where Bilstein offers it.
- Van or motorhome that wallows, leans or bounces: B6, or B6 Camper on a converted Sprinter.
- Truck or SUV at stock height: B6 4600.
- Truck leveled or lifted: B8 5100 for the lift you run, or 5160, 6112 or 8100 if you want a reservoir or the 60mm body.
Confirm the exact part in the Bilstein Shock Fitment Finder. Found it cheaper? We'll beat it.
FAQ
Is B8 stiffer than B6?
Bilstein doesn't frame it that way. On cars, B8 is shortened for lowered springs; on trucks, B8 parts are made for leveled or lifted heights. Each part is tuned for its own vehicle.
Are all Bilstein B6 shocks monotube?
No. Most are, but Bilstein's spec sheets list some van B6 struts as twin-tube. Check the internal design on the part's page.
What does the 4600 or 5100 number mean?
It is Bilstein's truck series name. The 4600 is a B6 for stock height; 5100 and up are B8 parts for leveled or lifted trucks.
Do B6 motorhome shocks need new springs?
No. Bilstein's B6 is designed to work on the existing springs at the original ride height.