My car is quite responsive when hitting the gas, but as the RPMs get higher and higher, there is only a small increase in power. Is there something wrong, or could I just not be use to a car with low amounts of HP/TQ?

 

You could find a facility with a dynamometer and get some hard numbers to see what the engine is really putting out, or you could invest in, say a Mustang GT500, or you could just face facts here and realize that your little 2½ liter engine that has been pushing that car for 16 years through over 150,000 miles is never going to run with the big dogs. The harder you push it, the sooner it's going to break. My advice is to take it easy, drive like you've got raw eggs taped to the pedals, put the top down and enjoy the scenery.