Watching the instantaneous fuel economy gauge in that hybrid helped me to retrain my accelerator foot. There was a marked difference in fuel used between a fast start, a normal start, and a leisurely start: from a low of about 10 mpg to a high of about 40 mpg.
I'd been getting less than 20 mpg in our van. I experimented with the most recent tank of fuel, with long, gentle starts. It feels weird, but I end up going the same speed as drivers who jack-rabbit out of the gate. I'm also typically less than 4 seconds behind them by the time I get up to the speed limit. Anyway, this last tank took us over 400 miles, and I managed to get 25 miles per gallon.
That's a 25% increase in fuel economy, just by changing my driving habits.