Sorry for not being precise, but I was estimating. If you need to know the gory details I actually drove .4 miles before I reset my trip B counter. I also only drive 8.8 miles so I was doing a little rounding and estimating how far I could stretch the last estimated 3 miles.
Made it 17.4 miles in EV the other day, with a mile to spare! Of course, it took me about 45 minutes on the socal freeways that day...
That's one of the many things that add up to make the PiP a really great car. In your case, not only did you go 17.4 miles in EV, if this was a non-hybrid like most of the other cars on the freeway next to you, the gas mpg would be horrible, even if a high mileage car. And compared to even hybrids, you wouldn't have had an engine cycling on and off a lot for those 45 minutes. Socal's made some major improvements in air quality over the last 30 years, but there is still a long way to go and the PiP helps a lot in the scenario you describe.
Whether you get 17 miles or 7 miles . . . here's a nice chart (from Tony on the 'mynissanleaf' site) that will show you how far you'll go, if you got a constant speed, and start with a full charge: http://dl.dropboxusercontent.com/u/35284720/postfiles/leafcharts/LEAFrangeChartVersion7G100.pdf It's pretty simple, if you're going fast, you'll only get a certain range per kWh. If you're going real slow, you'll go a whole lot farther. Thus, traveling at a constant speed under 35mph, you'll easily get over 6mile/kWh. Your range is thus a factor of kWh's available and speed (presuming moderate weather & level ground). .