Ok so if I use a commute I used to have as an example:
70 miles each way to work, chargers at the office (no idea if they were free or not, but lets assume not), I would charge twice a day, once at work, once when I get home. So call that $9 per day and I went in 4 days a week, so $36 a week and let's assume one more charge for weekend driving, call it 40 bucks. I used to spend around $80 - 100 a week on gas when doing that trip in my 335 (@ about 30 mpg, gas around $4/gallon). Not as big of a savings as I was expecting (obviously based only on some rough numbers here, and this is the first I've thought even this much about it…), but still very good and that's with a long commute. Driving around town instead of highway (more the intention of the i3), I would probably get more like 20 mpg in my 335, maybe 22 or 23 tops.
Sound about right?
As a side note, the GW bridge toll each day cost me more than the electric for the i3 would have
