2007 HYUNDAI ELANTRA User Comment / Complaint

I purchased a 2007 hundai elantra in january 2007. my daughter also purchased the same vehicle. we both noticed that when driving the speed limit everything on the road would pass us. i timed myself on a measured mile at 60 mph and discovered i was doing 55 mph. i started researching the internet and discovered it is a common problem. hundai has replaced some speedometers but apparently it does not correct the problem. it has occurred to me that this would also give you a better mpg indication than you are actually getting. have you received any other complaints about this and what is thoughts. my dealer had not heard about this problem.