35 mpg is much lower than is to be expected. A bit of troubleshooting is in order:

1. First things first, check you tyre pressures. Recommended is good enough (if not best).
2. Is the handbrake completely released ?
3. How fast do you drive on the highway ?
4. Describe you city driving -- how often, and the trip length.

3. Go out sometime when the traffic is light, and drive a return trip on the highway of about 10 miles, after the car has been running about 5 minutes, at 60 miles per hour. Reset your trip mpg meter at the beginning, and let us know what mileage you are getting. During the test trip, set AC to auto at 80 degrees, for comparison purposes.

R2-E2, 2G Prius.
Highway/City/Husband/Wife MPG: 56.5, as of 12/2005, 26K miles

Jac Nasser, Ford President: "We are planning to launch a hybrid version of
this car [P2000] within this year [1998]. We will also make FCEV available in
2004."