Which Bilstein: 4600 vs 5100 vs 6112 vs 8112

Bilstein makes five truck lines that sound alike. Here is the difference.

B6 4600 (stock height)

Monotube gas shock built for trucks at factory ride height. Direct replacement, no lift. If your truck is stock and you want it to stop floating, this is the part. Cheapest entry into Bilstein.

B8 5100 (0 to 2.5 in, leveling)

Same monotube design, built for leveled and lifted trucks. Fronts on most IFS trucks are ride-height-adjustable with multiple snap-ring grooves so you set the lift yourself, usually between 0 and about 2.5 inches. Rears come in stock and lifted-height versions. The most searched shock in America for a reason: it levels the truck and replaces the shock in one part.

B8 5112 and 5162 (leveling kits)

Bilstein's own kit packaging of the 5100 line. 5112 is a front-and-rear 5100 package. 5162 pairs 6112-style fronts with 5100 rears. Same parts you could assemble yourself, in one box.

B8 6112 (2 to 3 in coilover)

A 60 mm monotube front coilover with its own spring, sold as a front kit. Bigger body, more oil, more control, and a real spring rate chosen for the truck. Typically paired with 5160 rear reservoir shocks. This is the step from leveling into actual performance suspension.

B8 8112 ZoneControl (2.65 in position-sensitive coilover)

Bilstein's top truck coilover. Position-sensitive damping (soft in the middle of travel, firm at the ends), external reservoir, lift adjustable on the body. Priced near King and Fox 2.5; the choice comes down to ride preference.