Comparing Car Costs

Hey Mr. Green,
What's the cost of generating enough electricity with coal, gasoline, or biomass to power an electric car for 100 miles? Is it less expensive than engine fuel?--Lois in Glenview, Illinois

Juice for electric vehicles (EVs) is generally much cheaper than engine fuel, but it's tough to calculate exactly how much cheaper because of all the variables in cars (especially their size and design) and power plants (especially their location and the cost of energy to spin the dynamos). Such differences explain the wide range of electricity prices: from 7.6 cents per kilowatt-hour in North Dakota to 27.6 cents in Hawaii.

To get a handle on this, let's take the average residential price of electricity per kWh in the United States--currently 11.3 cents--and compare cars. Nissan claims that its plug-in Leaf gets 4.16 miles per kWh. So traveling 100 miles would cost just $2.72, or less if your utility offers off-peak rates. Even in a sweet little 40-mpg gas-powered car, the same trip would cost $7.50 when gas was $3 per gallon.
Remember, though, that those 100 miles can cost more than $50 in any kind of car, because fuel isn't your biggest car-related money-sucker. A new midsize sedan ends up costing 54 cents per mile when you factor in all expenses, including financing, depreciation, insurance, licensing, and so on, according to the AAA. Which explains why cheapskates such as Mr. Green don't own a car.

Though touted as environmental miracles, EVs aren't so innocent if their energy comes from power plants that burn fossil fuels and spew massive amounts of carbon dioxide. An EV that gets its charge from a coal-powered plant can be responsible for releasing almost as much CO2 as a conventional 40-mpg car.

Old pipes vs. bottled water

Hey Mr. Green,
I really don't want to drink bottled water, because tap water is cheaper and better for the environment. But my house was built in 1940, and the plumbing is of that same vintage. Our local water was tested and found to be safe, but I'm worried that the water from my own pipes may be contaminated with lead. Should I continue to use bottled water?--Eloise in Manhattan Beach, California

Since bottled water can cost 2,000 times more than tap water, you might be better off investing in new pipes, or at least a reliable water filter. Plus, bottled water isn't necessarily cleaner than municipal water; the plastic-encased stuff is often drawn from the same source.

As for the contamination potential of your home's aging pipes, lead is more likely to be found in the water of quite old or somewhat newer houses. Pre-1930s plumbing most often contains lead, though many old pipes may be safe because they've become encrusted with lead-blocking deposits over the years. Newer houses' copper pipes are suspect because, until it was banned in 1986, high-lead solder was used during installation.

To be certain about lead content, find a reliable lab to test your water by contacting the Centers for Disease Control and Prevention (800-232-4636) or the National Lead Information Center (bit.ly/leadinfo), which can also help you deal with other lead sources, like old paint. Lead--and other toxics--can be removed with filters OK'd by NSF International (nsf.org/consumer).

If your faucets have been idle for six hours or more, you can flush out lead by running cold water in the sink for a minute or two and in the bath for five minutes. But that's a lot of wasted water, so it should only be a short-term solution.