STANDARDS & COMMITTEES Wheel test specs revised SAE J3203 Wheel Radial Impact Test Procedure for Passenger Cars was published by the Wheel Standards Committee in January 2023. This document is a Recommended Practice that defines the test stand and procedure for evaluating radial impacts of all wheels intended for passenger cars and light trucks. The rationale for developing the document is to provide a laboratory test to simulate the impact imparted to a tire and wheel assembly from a pothole and/or an abovethe-road-surface hazard. The intent is to establish a uniform method and test stand for imparting damage and evaluating radial impacts. J3203 developers inspected thousands of wheels via their warranty returns in the United States. Roughly 90% of the damage to the wheel was located on the inboard flange only. Additionally, the magnitude of the damage to the inboard flange typically exceeded that of the outboard flange. This test strikes the inner half of the wheel only, replicating damage found in wheels inspected from service. The test stand is similar to that described in AK-LH 08, a European wheel specification. This test stand uses less mass and more drop height to replicate the impact phenomena seen in service. The mass of the striker is the least practical 42 April 2023 roughly 90% of the damage to the wheel from pothole strikes is located on the inboard flange only. allowing the drop height to be increased providing velocities that strike more like that found in service. Optionally, load cells are added to allow dynamic force measurement. The lower mass of the striker makes it easier to catch after the first impact and before a subsequential strike. The energy of impact is controlled through varying the drop height from 0.4 to 1.4 m. The repeatability is improved by the large difference of drop height. When the wheel is sequentially impacted from progressively higher drop heights, a curve of the permanent deformations relative to drop heights is available. This curve can project two regimes of deformations. The first regime is when air remains between the pinched tire sidewall and wheel flange. The second regime is when there is no air between the pinched tire sidewall and wheel flange which will be termed strikethrough. The second regime is far more damaging to the wheel, so the point of strike-through can be of importance to the vehicle and wheel manufacturer. n UPDATE Firestonehttps://www.sae.org/standards/content/j3203_202301/ https://www.sae.org/standards/content/j3203_202301/