Have you ever wondered why tire inflation is so important?  Well there are lots of reasons, first one being fuel economy.  Driving with low tire pressure can affect your fuel economy, and cost you a lot more in gas over the years.  Premature tire wear is another one, tires that are under inflated tend to be under more stress, your tires are already heating up and causing them stress so adding under inflated to that and it can cause the tires to fail.  Having properly inflated tires isn't really at the forefront of most drivers minds it is very important though.