The H&R OE Sport Spring set (MPN 50402-55) is a front and rear coil spring replacement for the 2008–2013 BMW 1 Series E82 in 128i and 135i trim. The manufacturer lists it at about 1.0 inch of front lowering and 0.75 inch at the rear. That cleans up the stance without the firmer ride of H&R's 29187 Sport kit, which targets about 1.8 inches front and 1.2 inches rear. Buy this set if you want a restrained, factory-style sport look and a comfortable daily-driving E82 suspension. Search terms it fits include E82 128i lowering springs, 135i OE sport springs, and BMW 1 Series sport springs.
Confirm your body style before ordering. The manufacturer's application listing covers the E82 coupe in 128i and 135i trim, and convertible fitment varies across sources, so check with H&R for any E88 car. For the install, owners on user forums describe a DIY job that takes a spring compressor and a full afternoon, with the front usually the easier side. One owner reported more than four hours on the front alone. The strut tower bar can block torque-wrench access to the inner top-mount bolt, so plan around it. Rear control-arm springs are the harder side to reassemble.
The manufacturer lists the OE Sport set at approximately 1.0 inch front and 0.75 inch rear. Its Sport spring (part 29187) is listed at approximately 1.8 inches front and 1.2 inches rear, so the OE Sport set offers a milder drop.
Fitment details for the convertible body style vary between sources. Confirm your exact model and body style with the manufacturer before ordering.
Owners on user forums report using spring compressors for the install, and note that the strut tower bar can block torque-wrench access to the inner top-mount bolt on the front.
This is an intermediate DIY job that needs a spring compressor, a set of sockets and wrenches, and a jack to hold the spring perch arm while you align it to the knuckle. Owners on user forums recommend a steering-knuckle clamp spreader rather than risking damage to the clamp. Work on the front first, then the rear, and make sure you have room in your schedule because the rear control-arm springs fight reassembly.
