Great site - thanks to all that participate by sharing info. Here's my story:
I picked up my new 2012 Leaf SL on Dec. 30th within the Washington, DC area. Had already put over 200 miles on it, but yesterday was my first real test - a trip from my house to Columbia, MD (my company's HQ location). Leaving at 6 AM, I normally do the 42 mile trip (one-way) in under one hour with the use of mostly highway driving in an ICE vehicle. Since winter temps had returned to normal around Washington, I planned on being safe and decided to try a trip limiting highway use as much as possible. I signed into CARWINGS on the PC and utilized the route planner function to calculate the shortest trip possible on a 100% charge. Results estimated a 4 battery bar, 33 mile, 55 minute trip (the normal route I'd use estimated 6 bars of battery use, by the way). Seemed like an adventure in the waiting, so off I went using the shortest distance approach.
I'll spare you all the details of the actual streets used for my trip (for those that aren't familiar with this area), but the end result mixed roughly 75% city 'stop and go' with 25% highway speeds (55-60 mph). The temperature was even colder at my destination (28 degrees, from 32). Driving all the time in ECO mode with zero heater use, I ended up using 6 bars of battery with 49 miles remaining on the GOM. The trip took an hour and a half (delay not traffic related, either). I couldn't help but wonder if I was going to make it home, so I L1 charged at the job for a touch over three hours giving me back 3 bars of battery. With 9 bars of battery for the return trip, I made it home with only 2 remaining - and a concern over whether or not I would have made the round trip without those three hours of L1 charging. To make things interesting, mother nature started dumping snow in Washington, causing some extra DC-area congestion.
While I don't exactly remember the remaining miles on the GOM, I believe it was in the teens. According to the car's multi-function LCD console, average speed for the round trip was 15.9 mph and m/kWh avg. was 4.2 (while CARWINGS indicated 4.3 -- in fact, the data from the two trips as reported from CARWINGS' site suggests I used a total of (including some regen) 16.5kWh for 72.2 miles.
So my takeaways:
1) Along each way, the trip had some pretty clear elevation changes, perhaps explaining the extra bars needed for each leg of the trip (as compared with the route planner's more pleasing estimation)
2) It was cold and only getting colder (battery temp was 4 bars all the time, however)
3) I know there are hidden miles/bars under the last two visible "red" bars that show, so I guess it's conceivable that I could have made it home without the extra 3 bar L1 charge. Or not, as I'm not sure yet. Do others concur with this?
Thanks in advance for any input. Can't wait for warmer temps to arrive.