What does Radial Tuned Suspension mean?

When steel belted radial tires were first introduced, some noticed a harsher ride on older existing model cars.

On subsequent model year cars, adjustments were made to correct for use with radials, and car makers would mention that in sales brochures, some even added badging to the cars.

Modern cars are all intended to have radials, so the term has lost any meaning.

It certainly has nothing to do with Chemistry.