General Motors shot back that the Volt's gas engine has no direct mechanical connection to the wheels but conceded that the gas motor is in effect driving the wheels at times. GM said it had not fully explained the system earlier for competitive reasons while it had patents awaiting approval.
Why should you care about this engineering altercation? Two reasons: First, the distinction means the car can go a lot farther before you need to plug it in (or fill it up). Second, because it can have a big effect on how much the car will cost you. For most people, Federal and state tax credits are crucial in bringing down the cost of the pricey $41,000 Volt. (See Electric Cars: Buy or Lease? ) The question is whether the Volt is a plug-in electric like its competitor the $32,780 Nissan Leaf, or if it is, as critics assert, more like a plug-in hybrid, which is subject to fewer incentives in some states. As a driver, the big difference comes when you head out on a long road trip: The Volt can keep going once the battery has run down after 25 to 50 miles. (Nissan says the Leaf has a 100-mile battery range, then has to be recharged).
Here's a look at the financial facts of the case:
Will the Volt get the full federal tax credit? Yes. The federal credit depends on the size of the battery in the vehicle. It starts at $2,500 for a battery measured at four kilowatt hours and steps up to a maximum $7,500 for batteries of 16 kilowatt hours and larger. The Volt and Leaf meet that maximum standard, as does the Toyota Prius plug-in hybrid planned for release next year. The credit, due to expire in 2014, will also end for any given manufacturer after the sale of 200,000 electric vehicles. Sen. Carl Levin (D-Michigan) proposed this week that the cap ought to be lifted if the government truly wants to encourage electric vehicle development.}
Will the Volt get all state tax credits? It will get most but not all of the extensive state tax credits for electric cars. The Volt will not qualify for a $5,000 rebate from California (better than a tax credit because you get a rebate check soon after the purchase). California's rebate depends in part on tailpipe emissions and the Volt does not qualify as an Advanced Technology Partial Zero Emissions Vehicle (AT-PZEV) in California's convoluted classification. That is because of air pollution problems during cold starts, according to GreenCarReports.com. The Prius plug-in hybrid, on the other hand, will qualify for the rebate because it's equipped with technology designed to cope with the start-up problem. For the same reason, Volt will miss out on another cherished California perk available to Leaf and Prius plug-in owners: the ability to drive in high-occupancy vehicle commuter lanes even with only the driver on board.
What about the charging equipment? Installing special 220-volt home charging units will average about $2,000. A federal tax credit for half that is in effect for any unit bought before the end of 2010. The higher-voltage charger will cut in half the full-charge time on a regular 110-volt household outlet. On the regular voltage, the recharge would take eight hours for the Volt and 16 hours for the Leaf, which has a bigger battery pack. You can apply for subsidies for the special charger from other federal programs if you live in areas where the Volt and Leaf are being sold first. That includes Arizona, California, District of Columbia, Oregon, Tennessee, Texas and Washington.
What about gas mileage? The Environmental Protection Agency has not yet announced its plan for assigning mpg-equivalent ratings to plug-in vehicles. GM rashly came out last year and said the Volt would have a 230 mpg equivalent based on early EPA methodology -- but then GM had to recant. Popular Mechanics, in a test drive, calculated that the mileage, including the distance traveling on battery power, was 37.5 mpg in the city, 38 mpg in highway driving. That is significantly lower than the rating for a regular hybrid Prius of 51 mpg in city driving, 48 highway. Of course, a commuter who drove a Volt less than 25 miles a day and recharged at night wouldn't buy any gas at all. And overall emissions of pollutants and greenhouse gases would depend on how the electric power was generated. (See Electric Cars: How Green Are They Really?).
Photos courtesy of the manufacturers
More from MoneyWatch
Toyota Offers Free Maintenance: Is it a Good Deal?
Car Safety: New Crash Tests Reduce Star Ratings
Toyota Recall: Safe Stops and Crash Tests
Used Hybrid: Why You Should Consider Buying One
Gas Mileage: New Smaller Engines Save Money, Keep the Power