A new, low cost, structural reaction injection molding resin has been developed for automotive applications requiring high mechanical strength and impact resistance. Primarily targeted at bumper beam applications, this new resin also displays very good thermal properties which make it a unique candidate for use in assembly sequences requiring high temperature exposures. Thermal and mechanical properties are presented as a function of glass level and glass configuration. At levels of over 50% by weight reinforcement, flexural modulus values of more than 14 GFa (ca. over 2 million psi) and coefficients of linear expansion comparable to steel are achievable. The resin has a unique “snap cure” reactivity profile that permits long shot times while maintaining demold and cycle times to the levels required for low cost targets in automotive components.