Well they are on our small tire car. However look at 99% of the Comp Eliminator or the faster SS cars and see how many of them are using them? It will ad weight in the worst place possible and that is rotating weight. You also wont find them in the alcohol classes either. They are popular in TS and TD as well as S/G, but are they needed or make the car any better/quicker, IMO that is debateable