@Peter XX, I also got 52 mpg in my 2008 Prius before upgrading to a plug-in. I've averaged 68 mpg ever since (total miles divided by total gallons). It really depends on how you drive and the conditions in which you drive. The new Fiat engine is a very exciting achievement. I agree that it would be great as a range-extender or in a hybrid.

Retrofits would only be done by a few enthusiasts unless they come from the manufacturers and are handled by regular dealers and repair shops--and gasoline prices have to be high enough to be a sufficient motivation. A gradually-increasing gasoline tax would be the easiest way to move EVs and PHEVs along. But if we did have a sudden shock in the price or availability of gasoline, having a viable retrofit industry would be a lifesaver. It seems a shame to waste all those perfectly good cars because their drivetrains need to be replaced, but the older cars are too heavy to be of much use with the available EV drivetrains and batteries--the range is too low. From that point of view, it makes sense for EVs to be originally designed for that purpose.

There's a plausible rationale for the cellulosic ethanol tax credit, but not for corn-based ethanol. I'd prefer not to be adding to the federal debt by the counter-productive subsidies to turn corn we shouldn't be growing into fuel that is no better for the environment than petroleum.

Nordic: Neil is correct, EVs emissions are lower, even when grid-powered, and that advantage will grow with time, as the grid gets cleaner. I charge my car at night, and I don't mind the slow speed of charging. Fast charging will be best done in conjunction with smart metering and charging systems that can tell when the power is cheapest and most available. Detering people from peak time charging can be done with a properly-designed incentive system. The $300 billion or so that goes out of the coutry per year for foreign oil is a huge opportunity to create a domestic industry to power cars. Vehicle electrification will have huge benfits enconomically and environmentally.

Consumer acceptance of electrified (EV, EREV, PHEV) vehicles hinges on being able to charge the batteries often enough to make the vehicles practical to use. As the price and capacity of batteries improve, charging stations may become less necessary, but in the interim, there is a real risk of a consumer backlash if consumers buy cars that they can't use or that don't seem to be worth the hassle. We need to make charging stations as ubiquitous as pay telephones used to be. It will take bold action by cities and states to foster charging station networks in order to break the chicken-and-the-egg cycle. Consumers will be reluctant to buy cars that they might not get full use from, and without a groundswell of demand from EV owners, companies may not be interested in investing in charging station networks.

It won't take us very long to find out. Toyota is test-marketing small-battery PHEVs. Given the explosion of development activities in all sorts of battery chemistries and packaging, I'm pretty optimistic about the chances of multiple low-cost battery designs coming to market over the next several years. And, yes, lots of people have access to a 120V outlet at home, but given the limited battery range, it really is troublesome if you can't charge up at work (my big pet peeve with my PHEV). And, don't expect many people to actually get the touted 120mpg that Toyota has promoted for the PHEVs--that depends on what percentage of your driving can be electric. I only get 100mpg for the first 30 miles, so long trips are pretty disappointing.

Imagine a world where businesses can "take delivery" on power when it's cheapest and store it until it's needed, or even resell it when it's profitable to do so. That will require storage that is cheap enough and has a low enough loss rate to make it worthwhile. Once wind and solar are cheap enough--and storage cost-effective enough--so that it is profitable to store excess power rather than waste it, that will turn wind and solar into "baseload" power, making a 100% renewable energy grid practical.

DanM: If you're tired of waiting for the Volt, you can do I what I did and put a lithium battery in a Gen-II Prius. That's available now and costs less (even considering the 1K incentive for the battery vs. the 7.5K incentive for the Volt), and the Prius has a very good track record for reliability. Even when the Volt is released, it will take time for GM to work the bugs out. By the time GM rolls out the Volt, Toyota will have its own production model PHEV Prius with all the advantages of a decade of customer experience with the platform.

in reply to Mark BC: Extended-range EVs (like the Volt) could be designed more simply than the Prius, but because the Prius already has the advantages of being fairly far down the cost curve (after being on the market for more than a decade), the Prius still wins out on cost. The $10K premium that I paid to convert mine to a plug-in puts the price way below what the Volt is expected to be selling for. If Toyota can come up with a decent battery configuration for less than a $3K premium over the standard model, they'll have a winner. Detroit would have to be willing to initially take big losses to be able to catch up to Toyota's lead.

Local charging infrastructure is one key element in building public enthusiasm for plug-ins. To do that, we need connection standards and incentives for employers and landlords to set up charging stations for employees and tenants. Given that employers and landlords face big up front costs with no way to recoup those costs, we need a way for a third party to install and operate the charging stations, with some sort of subscription service for end-users. There has to be enough of a initial subsidy to roll out the system in a way that landlords and other business owners get some benefit from agreeing to host the charging stations. Currently, I can rarely charge my PHEV anywhere but home. It's very frustrating.

Tar sands extraction clearly needs to be phased out, not expanded. Even if they could innovate to reduce emissions for extracting oil, the product itself is so polluting to use that continuing to extract tar sands makes no sense.

The$7500 tax credit for plug-ins will help launch them. It will take high gas prices or continued subsidies or battery breakthroughs to bring the cost down. But acceptance hinges not just on getting people to initially buy some of the vehicles--but on drivers having a positive experience as users and owners. Part of this will be government support for a rollout of charging stations. The limited electric range of PHEVs and BEVs with affordable batteries means that charging stations have to be available where cars park--homes, apartments, businesses, stores. My main frustration with my PHEV is the lack of being able to charge it anywhere but home. I think that Toyota is very much on track with a limited range PHEV to test the waters. That will keep costs down for the first generation and it should help drive demand for charging stations. Once the public becomes more familiar with BEVs and PHEVs a cost and demand tipping point should be reached where BEVs and PHEVs become ordinary and manufacturers will be less reluctant to offer new products.

Retrofitting existing vehicles has enormous potential to be "green" from a resource reuse perspective (i.e., not treating cars as throw-away items), but it's something that the auto manufacturers have been loathe to touch. It would be great to encourage innovative companies to design energy-efficiency retrofits--like better drivetrains, better tires, lightweight body panels and other components. I can imagine a second life for older cars with worn out drivetrains--conversion to EVs.

This is a very sensible first attempt at a mass-market PHEV. The larger Hymotion battery pack works great, but it's too expensive (for now) to have mass-market appeal. The PHEV Prius has a much better chance at market acceptance than the Volt; the Prius will come to market first; and as better battery options become cost-effective Toyota will no doubt offer longer-range options. Enough Americans comute (each way) less than the EV range of this PHEV Prius, that assuming that they can charge at both ends, having a plug-in makes sense. Hopefully, this will give employers, businesses and landlords a good nudge in the direction of building out charging infrastructure.

So, this means that the U.S. has an adequate domestic supply of lithium for the immediate future, and the fearmongering about swapping dependence on foreign oil for dependence on foreign batteries is bunk. We can build a domestic battery industry and if push comes to shove and we can't get cheaper foreign lithium, that we have enough of our own to support a thriving electric car industry.

AI Vin's point about gasoline production getting dirtier just means PHEVs will get more and more attractive as compared to conventionally-fueled cars. The real truth about CA power generation is that SoCal gets lots of dirty power from out of state. As we make more of our own from renewables (or buy more renewables) that will reduce the percentage of dirty power CA uses. On the bright side, we can support millions of PHEVs and BEVs charging at night with no more pollution that is being generated now, so that means comparing tailpipe emissions with conventional cars is quite fair. Since the average passenger load in the U.S. is about 1.3 (2 out of three cars having only the driver), all cars pretty much are on an equal footing. Solo driving still dominates. So, comparing the average car's mileage to a PHEV's mileage really is pretty fair. Solo driving a Hummer 50 miles a day pollutes a lot more than solo driving a PHEV-equipped Prius the same distance.

Both figures are useful (tailpipe and total), but in practical terms, tailpipe emissions are what we can measure and what is useful for emission comparison purposes. We control power plant emissions at the plant, and that is declining towards zero. When you consider the question of how to reduce total emissions, we have to act separately on each source. That we can cut tailpipe emissions by electrifying cars is a very good thing and in a world of declining power plant emissions, it is fair to compare plug-in hybrid emissions with traditional ICE emissions. . I've been getting 73 mpg overall average on my commute with my Hymotion-equipped Prius, and that would be closer to 90 if I could charge at work. Plug-ins really DO work, and they are a great way to reduce emissions. Here in CA, we're aggressively driving down our power plant emissions, and so plug-ins are especially valuable in CA for promoting air quality.

The Hymotion upgrade was costly, and if/when Toyota does its EREV version of the Prius, it will need a more powerful electric motor, but as a means to improve gas mileage, the Hymotion upgrade really works pretty well with the existing Prius. You can either hypermile or drive in your normal style, and you'll get better gas mileage up until the Li-ion battery is fully discharged. For the first 30 miles of driving, I get very nearly 100 mpg, and that is mosly on freeways. A more powerful electric motor would be nice, but until battery capacity catches up with what the motor would demand, the risk is that you'd just drain the battery quicker. I'm actually quite pleased with the Hymotion upgrade and I'm sure that with the right battery, range and price point, that Toyota could easily roll out a PHEV version of the Prius that would be a market leader. They're SO close already.

Maybe it's time for some leadership from Washington. Raising the gasoline tax is something we have to do, even though it isn't popular. It would be tragic to wait until oil prices go back up and strangle the economy before we agree to do something.

The survey may be misleading in that pretty much anyone would say no if you asked if they wanted to pay "a lot more" in taxes. I wonder what people would say about "a little more"? I agree that we would hardly notice a gradual tax increase on gasoline. Gas prices WILL go up, since OPEC has discovered that we will indeed pay $150 a barrel, so we might as well capture some of that increase in the form of taxes that can be used to get us off of oil for good. We absolutely WILL pay more for gasoline, so we might as well get on with it and put the extra money to good use. Why let foreign oil producers pocket it all?