Abstract: A precipitated amorphous silica product particularly useful as a highly dispersible filler to elastomeric compounds, especially rubber passenger tire tread formulations. The invention has a CTAB specific surface area of about 10 m.sup.2 /g to less than 140 m.sup.2 /g; a multi-point BET surface area of about 50-261 m.sup.2 /g; a 5% pH value of about 5.0-8.5; a DBP oil absorption of about 160-310 cm.sup.3 /100 g; a linseed oil absorption of about 150-300 cm.sup.3 /100 g; a projected surface area of no greater than about 4000 nm.sup.2 ; and a pore volume ratio of pores ranging from 175 to 275 .ANG. in diameter to all pores less than 400 .ANG. in diameter of about 10% to less than 50%.

Abstract: The invention is a natural rubber compound containing a precipitated amorphous silica filter. The silica has a CTAB specific surface area of about 10 m.sup.2 /g to less than 140 m.sup.2 /g; a multi-point BET surface area of about 50-225 m.sup.2 /g; a 5% pH value of about 5.0-8.5; a DBP oil absorption of about 160-310 cm.sup.3 /100 g; a projected surface area of no greater than about 4000 nm.sup.2 ; and a pore volume ratio of pores ranging from 175 to 275 .ANG. in diameter to all pores less than 400 .ANG. in diameter of about 10% to less than 50%.