Great factual article, I like facts as apposed to anecdotal opinion.
Here's some interesting article highlights.
Initially, silica was used almost exclusively in high-performance tires for sports cars to help balance the sticky properties of grippy tires with reduced friction for quicker response and handling. However, with the need for greater fuel efficiency, silica has found a new purpose with low rolling resistance tires commonly found on electric and hybrid cars.
Budget tires, by comparison, contain little of this high-tech stuff. Few contain much, if any, silica. There's also less widespread use of natural rubber, and more reliance on lightweight materials like fiberglass and even Kevlar. Harder synthetic rubber in budget tires has often been cited in maintaining a tire's longevity, but it's usually at the cost of on-road control, handling in emergency situations, road noise, and vibrations felt during driving.
Hankook took particular pride in showing us its Optimo H426 touring tire, which serves as original equipment on some Fords, Hyundais, Kias, Lincolns, and Volkswagens. Comparatively speaking, the Optimo H426 uses more silica than what most other manufacturers use in similar tires, also adding to cost and complexity. Hankook spokespeople said the process for mixing tires rich in silica is more complicated, but it's what the company has to do to gain some advantage, slowly chipping away at the market share maintained by more-established players.