The H&R 52428 is a four-spring Sport kit for the 2006–2013 Lexus IS350 2WD sedan. The manufacturer lists it at approximately 1.4 inches of lowering in front and 1.3 inches in the rear, which closes the factory fender gap without the harsh ride of a race setup. Owners on user forums describe the H&R Sport springs as progressive-rate and say the car corners with less body roll than stock. The kit also lets you keep your factory dampers in place while you lower the car, a real cost advantage over a coilover system.
Confirm fitment before you order. The manufacturer's application guide lists this kit for 2WD, non-convertible models, and owners on user forums note that AWD IS350s need H&R's separate AWD set. Real-world drop varies: one forum owner reported closer to 2.0 inches front and 1.8 inches rear on a car with aftermarket shocks, so details vary and you should confirm with the manufacturer if you have a specific ride-height target. Many owners also pair these springs with upgraded dampers for better control on rough pavement.
The manufacturer lists this kit for 2WD, non-convertible models only. Owners on user forums say AWD IS350s need H&R's AWD-specific set.
The manufacturer lists approximately 1.4 inches in front and 1.3 inches in the rear. Owners on user forums report that results vary with wheels, tires, and shocks, so confirm with the manufacturer for your setup.
Owners on user forums commonly recommend an alignment after the install. Opinions differ on whether new springs settle over time.
Coil spring replacement is a moderate-difficulty job that requires a spring compressor and standard hand tools. One owner on a user forum had a shop complete the install in about 1.5 hours, which gives you a reasonable time benchmark. Plan on an alignment afterward, since lowered ride height changes camber and toe. Forum write-ups for other IS generations describe the process in detail, but their steps may not match a 2006–2013 car, so check them against your own vehicle.
