I mounted my bottle sideways, against NOS recommendations. I did so to make optimum use of available room in the vehicle. If possible, mount the bottle with the bottle valve pointing at the front of the vehicle. This way you should be able to pick up nitrous better when accelerating. I tilted my bottle slightly to make up for my incorrect mounting job. The bottle should be mounted at about 30-45 degrees with the label on top to make sure the siphon tube is picking up from the lowest point in the bottle.