Welcome, I'm driving a Prius for similar reasons. 20 years of making a 135 mile a day commute. Driving a few performance cars over the years with the best milage from my Infiniti but it was still only about 20-22 mpg. My run is all freeway speeds from 85 to 5 mph depending on traffic patterns. Overall the Prius gives me about 43 mpg so I've cut my fuel costs in half saving me over $ 3500 a year
Well we have almost 5000 miles under us now and have learned a few things, I got 57 mpg yesterday evening coming home UNTIL it got dark and colder, still made the trip at 55 mpg, running 65 to 75 mph. Have gotten 47 mpg average since I purchased it, leave it in normal and just drive it as I normally would any other car, it just does so well why go to extra pains for a couple more mpg? Really hustled ( 80+ ) several times as I got a late start heading home and just wanted to be there, 49 mpg, cost me an extra buck to get there, big deal. Overall, I couldn't be any happier with my little car, got my satellite radio going, I love the quiteness, can't hardly hear any exterior noise, love having people asking about it, now I just need the off brand ( PRIME WELL? ) tires to wear out and get a set of MICHELIN ENERGY SAVER A/S on there and log some serious miles.
I cruise at about 72 mph for most interstate driving, which is most of my driving. My actual mileage is about 47.1 over the first 50K miles for the car. Given how much you drive, I doubt you want to slow down too much. I predict you will like the Prius a lot.
The more you drive the Prius, the more you will come to admire it. I know I do, its' been 4 years of drining bliss. I tried a test drive of other cars: the Volt nad the Leaf - was not impressed with either one of them. The high purchase and limited range eliminates them from my commutes. Enjoy your ride. DBCassidy