You need to go to dealer to see if upgrade is installed. There is no way to tell from vin number. The upgrade maybe adds 1 mile per gallon to the mpg. The upgrade changes the way the IMA operates in stop and go driving and does little at highway speeds.

Thanks for the quick response. I figured that would be the answer. It probably wouldn't be a bad idea to bring a copy of the TSB to make sure the dealer knows what I'm talking about...

I have a 2007 HAH with about 2500 miles on it. We live in DFW Texas and drive about 50% on the highway. The overall mileage we have gotten on it since we have owned the car is 29.0 On our last trip to Austin we got 38.

Chuck