The H&R 29126 is a Sport Spring kit for the four-cylinder Toyota Yaris, a front and rear coil spring set that lowers the stance and center of gravity. The manufacturer says its springs are made from (hf) 54SiCr6 spring steel, and that the Sport Spring line uses a progressive rate where the application allows. All H&R springs are crafted from a special (hf) 54SiCr6 spring steel to ensure premium quality and performance. All H&R OE Sport Springs, Sport Springs, Super Sport Springs are progressive when possible for the application.
Why choose this over stock or a bargain spring? The manufacturer positions this line as its top seller, and it targets a lower center of gravity and less body roll while keeping daily ride comfort. H&R Sport Springs lower the vehicle center of gravity and reduce body roll for better handling. Progressive springs stay compliant over broken pavement yet resist harder compression under cornering loads, which suits a commuter Yaris that sees occasional spirited driving. Owners on user forums commonly lower these cars on factory struts, then shorten the bump stops to avoid bottoming out, so budget for that extra step.
The manufacturer says H&R springs fit the same way stock springs do. If the spring is the same on both sides and fits the same either direction, then it is correct to install the spring with the closer coils "up". If one end is smaller than the other, match the factory orientation.
Owners on user forums say a spring compressor is needed to remove the factory front springs safely, and warn that an improvised clamp setup can cause serious injury.
Owners on user forums report running lowered Yaris springs on factory struts after shortening the bump stops to prevent bottoming out. The manufacturer's own guidance on shock compatibility for this specific kit was not confirmed during research, so verify with the manufacturer if you plan to keep stock dampers.
Experienced DIYers can do this at home, but the front is the harder side. You need the spring compressor to remove the stock front springs safely. Owners on user forums suggest removing the cowl for access, and note that the sway bar link nuts can be really tight, especially in regions that use salt on the roads in winter, so heat or penetrating lubricant helps. Rear springs are generally simpler. Watch for the 12mm bolt that holds the brake line to the front strut. Measure ride height before and after the job, and plan a wheel alignment afterward.
