Nissan Versa

I have been driving a used Nissan Versa for about 3 months now.  I get around30-32 miles per gallon.  I am not really impressed.  This does seem lackluster for a 4 cylinder.  My Mercury Grand Marquis got 30 mpg and it had a v8 engine and weighed 4000 pounds.  I think it is not a good idea to give up safety for a couple of miles more per gallon.  I will probably keep the Versa at lest for now.  However, I will be buying another Mercury Marquis as soon as I find what I want.  I will also be buying a Dodge Ram.  I am not much on the smaller cars.  Seems to me, if we are giving  up the safety of the larger cars, we should at least get around 50 mpg.  I just feel like I have been ripped off.