© istockphoto [dim_it:pic_desc]A PET bottle weighs around 37 grams, a glass bottle around 600 grams; in other words: 16 PET bottles weigh approximately as much as one glass bottle of the same volume. The low weight of the PET bottle presents a significant economical as well as ecological advantage: because PET bottles are so light, the cargo hold of a truck can be fully used without overloading the vehicle, and fewer vehicles on the road means less environmental pollution from car exhaust. (Photo: istockphoto)[/dim_it:pic_desc]