Cured rubber compositions with reduced divalent metal levels and improved physical properties are prepared using methods that limit or avoid a deleterious side reaction, and that make activator compounds available only during cure and not earlier during mixing. Specifically, the presence of activator soap (or of components that can form the activator soap in situ) and silica filler together is avoided or minimized in process steps where the temperature would tend to be above 100° C. or 110° C. The use of ZnO for example can be reduced by as much as 90˜95% in a typical rubber compound.