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The car of the future must not only meet stringent emissions standards, it must be more fuel efficient and cost less without compromising occupant safety. Much progress has been made in reducing emissions via improved engine designs, better engine control systems, and advanced catalyst technologies. Initial assessment by MIT researchers shows that by 2020, conventional vehicles will be twice as fuel-efficient, half as polluting and cost little more. This paper, which is in support of the goals of PNGV (Partnership for New Generation of Vehicles), focuses on lightweight glazing of the future car with the targeted weight reduction of 30% to help improve corporate average fuel economy. To this end, much work has been carried out in designing and testing the conventional laminated safety windshield which accounts for 62% of the total glazing weight.

Tempered float glass is commonly used for both side windows and backlites in the automotive industry. The success of such products is primarily attributed to high level of residual compression, following tempering, which provides abrasion resistance as well as 3X higher functional strength to sustain mechanical, vibrational and thermal stresses during the vehicle's lifetime. Certain applications of tempered glass, however, require mounting holes whose surface-finish must be controlled carefully to withstand transient tensile stresses during tempering. Simultaneously, the nature and magnitude of residual compression at the hole must provide sufficient robustness to bear mounting, vibrational and thermal stresses throughout the life of the vehicle. This paper presents (i) analysis of residual compression at the hole, (ii) measurement of biaxial strength of annealed glass with hole at center, and (iii) measurement of biaxial strength of tempered glass with hole at center.