I had a discussion regarding this issue with a coworker a while back, some via email.

One site claims that their PHEV uses electricity that equates to $0.75/gallon gassoline.

Fair warning: these are old links and I did not check to see if they still work.

http://www.pluginpartners.org/plugIn...icBenefits.cfm

The only real technical data I found, on a real product:
http://www.edrivesystems.com/faq.html

Some of the "gasoline cost equivalent" math uses a comparison to a vehicle that gets 25 mpg, which I don't think is reasonable. Also, many of the estimates I have seen use the cost of electricity as $0.08 to $0.10 per kilowatt hour (KWH) which I also do not think is reasonable. That is likely the cost for the lowest priced tier, but owning a PHEV would put most people into the highest priced tier. I think it makes more sense to do the math based on the highest priced tier. That cost can vary greatly based on electricity provider.

I am actually very pro-PHEV and am looking forward to the technology making it to the mass market. I just think that the marketing and sales pitch needs to be upfront and honest about the costs. I realize this is a huge contradiction. Kinda like expecting a first-date to tell you what they are really like!