Disclosed are methods and lubricant compositions for reducing wear in internal combustion engines lubricated with a low phosphorous content lubricating oil. The restraint system includes at least one gas generator housed within the dash panel and an inflatable cushion in fluid communication with the gas generator. Advantageously, according to an aspect of the present invention, the reconstruction of the image may be performed iteratively, wherein the updates are weighted with the intrinsic statistical error of the measured photon counts.