OBD2 'fuel saver' boxes can actually increase costs by damaging your car - do this instead

ZDNET examines cheap “OBD2 fuel saver” dongles and finds they are scams: teardowns show only a timer chip, LEDs, resistors and loose wiring, not any legitimate engine remapping capability. The article warns these devices can short, cause fires, or leave pins lodged in a car’s OBD2 port, and recommends conventional fuel-saving measures (proper tire pressure, smooth driving, reduced weight, and maintenance).