Is that spare tire taking up room in your trunk? While many of the experts were advising drivers to clean out the trunk to increase gas mileage, not one knew General Motors was making plans to eliminate spare tires entirely. In its new Chevy Cruze, GM equips the compact with an on-board tire inflator kit. General Motors claims eliminating the spare sheds approximately 26 pounds in total car weight. If your tire is irreparable (even beyond the kitâ€™s assistance), drivers can press GMâ€™s trademark OnStar button on the rearview mirror to request emergency roadside assistance.