I like the 3.55's. I don't do the expressway thing much though. 40 miles on Sunday was enough to get me looking for a good exit. I wouldn't trade to anything higher because I might lose my chirp when it hits third. I did notice that you get a lot of respect on the expressway with these old cars. People can't believe that you have one that is actually not a trailer queen and you can drive it some distance. I got a dozen 'thumbs up' signs in those 25 minutes.