On the highway at traveling speed (55 /70) when we come to a hill the car struggles to stay at that speed and usually drops down to close to 30-40 mph but the rpm' rise up, and the rpm's rise up really fast and if it goes over 3k rpm's it makes strange noise and occasionally smokes and smells. If you stop the rpm's from rising past 3k it doesn't smoke or smell, but the speed still stays low, its even difficult to climb hills at lower speeds, and its more difficult to climb a hill if the AC is on.

Update from Oct 25, 2015: I was given the wrong year the vehicle is a 2007