Went to visit my dad in Central, Pa over the weekend. It takes about 4 hours to get there. We done this trip many, many times in a Geo Metro. The Metro always had issues climbing the mountains. Some were so steep we would end up in 3rd gear going 35 MPH trying to climb while getting passed by everyone including loaded dump trucks. We would normally average about 44 MPG doing this trip.
The Mirage was a completely different story. This car was able to climb the mountains with no problem at all. I only had to downshift into 4th gear once because the old man in front of me was going so slow up the hill. My Mirage with the P195/50R15 tire/wheel combo averaged 42 MPG on the way there and 39 MPG on the way back fighting a strong headwind. I am sure the stock wheels and tires would have netted better MPG's, but I am not complaining.
Very happy with this car so far. We currently have about 5,000 miles on the odometer and had no issues at all.