I don't do anything special. I try to keep the car rolling as often as possible, controlling the speed using the accelerator by anticipating events and potential obstacles as far ahead as possible so that I can slow the car down gradually rather than rushing towards traffic lights or slow moving traffic and then being forced to use the breaks. I use the same approach on motorways and often manage to drive anti-clockwise from Junction 13 of the M25 to the Folkestone Eurotunnel exit without touching the brakes.
I find that when the battery is fully charged the car will run at 40miles per hour for quite a distance. In london traffic, the car spends most of the time running on battery power and then re-charging when the traffic comes to a stand still. Not using the Air Conditioning also helps in Winter. I suppose it also depends upon how your battery charges - I can get often get mine to charge to full green bars as I descend down a steep hill towards the village I live in.
I also only use premium unleaded from Shell wherever possible and BP on other occasions.
When I had a MkII RX300, I used to average 20-22mpg for every day driving, and 25-27mpg on longer runs.
Thanks for the tips. I am going to try it. Today, I took the car on the highway and the average I did was only 27 MPG - which is far from satisfactory. I also find that I cannot sufficiently get the battery to be charged to the maximum green bars. The highest it can go is 2 to 3 bars above the mid-point. How can I get it fully charged without the benefit of going down slopes? should I get the car checked? Many thanks!!