I can't believe I missed this thread, I actually found it doing a google search for phev Insight
So far I have been running mine for a week with the parallel setup, charging about 1.2 KWh every night which works out to just under 10 cents worth of electricity at 7.2 cents a KW. My in town stop and go driving on my 10 mile daily commute (spread out over three different times) as been as high as 100+ mpg and as low as 70 mpg. Normally I am around 50mpg - 60mpg for the same route. I figure gas has been costing me about 5.8 cents a mile @ 60mpg. With a 85 mpg average it is at 4.1 cents a mile. With PHEV I can spread out the batteries over the ten miles, for an additional 1 cent per mile cost on electricity, for a total of 5.1 cents per mile.
Basically, to make it economical, at $3.50 a gallon for gas, and 7.2 cents a KWh or 10 cents a charge. These numbers will also vary depending on size of the batteries, the length of the commute, etc.:
For my 10 mile daily:
If you got 55 mpg before, you need to get 65 mpg to break even
If you got 65 mpg before, you need to get 80 mpg to break even
If you got 75 mpg before, you need to get 95 mpg to break even
If you got 95 mpg before, you need to get 130 mpg to break even
So it all boils down to the cost of gas and electricity. As gas gets to be more expensive the numbers shift in favor of PHEV. So far I'm past the break even point, minus the $500 I have into batteries, charger, and parts for the parallel mod. Also learning what techniques work best for PHEV will raise the average mpg.
