Three-dollar-a-gallon gas triggers a lot of finger-pointing. Democrats say Republicans have coddled the oil companies and ignored conservation and alternative fuels. Republicans say Democrats have blocked drilling and refinery construction.

First, it generally doesn't pay to buy a new car if the old one still runs. Keeping an older car going as long as possible spreads the purchase price over more miles, helping to reduce the cost per mile.

Also, car values fall, or depreciate, much faster in the first few years. So the more often you buy new cars, the more you lose to depreciation.

Second, these sexy hybrids don't look like a very good buy. I do hanker for one, but a new Honda Civic hybrid costs nearly $24,000, a Toyota Prius about $22,000.

My 12-year-old Ford Sable station wagon is still running pretty well and is long since paid for. And it would fetch almost nothing on a turn-in, meaning I'd have to shell out the full $24,000 if I wanted the Civic.

The Civic gets about 51 miles to the gallon on the highway, more than twice what the Sable gets. With fuel at $3 a gallon, that would save about six cents a mile.

But I make no loan payments on the Sable, while a loan on the Civic would cost upward of $400 a month. I'd have to drive nearly 6,700 miles a month for the six-cent-a-mile gas savings to justify the $400-a-month loan payment. I rarely drive more than 12,000 miles a year.

You could do a more detailed analysis, accounting for things such as the higher maintenance costs on my old Sable - and the higher insurance costs on the new Civic.

But most reports I've read agree that the hybrids' fuel efficiency doesn't offset their premium prices. If the hybrid price premium is $3,000 to $6,000, as many analyses assume, it would take five to 10 years for the hybrid to save money over the standard.

So even if the engine has fallen out of your old clunker and you must go buy another car, it probably makes sense to choose a lightweight standard vehicle over a hybrid.

To test this, I went to the AAA's Auto Buying Wizard at http://www.aaa.com and searched for "economical" cars that get at least 35 miles to the gallon.

The cheapest was the $9,350 Chevy Aveo, a five-seater said to get 35 miles a gallon on the highway. That's 8.6 cents per mile versus 5.9 cents for the Civic hybrid, assuming $3 gas.

The Aveo is $14,650 cheaper than the Civic. Although the Civic's fuel use is 2.7 cents less per mile, it would take nearly 543,000 miles of driving for that saving to offset the Civic's higher purchase price. Even I don't keep a car going that long.

And then there's the Honda Civic with the standard engine. It gets 38 miles on the highway and costs $14,760 - nearly $10,000 less than the Civic hybrid. The hybrid's 2-cent-a-mile saving would start paying off after you'd driven a mere 462,000 miles.

Tuesday's item on required minimum distributions from traditional IRAs brought a number of questions from readers about which table to use in these calculations. The RMD, required after the account holder turns 701/2, is figured by dividing the IRA accounts' value by the life expectancy from one of three tables in IRS Publication 590.

Table 1 is for beneficiaries - people who inherit IRAs from others. Table 2 is for IRA owners with spouses who are more than 10 years younger and are the sole beneficiaries. Table 3 is for IRA owners who are unmarried, who have spouses 10 years or less younger, or who have spouses who are not the sole beneficiaries.

For a 71-year-old, Table 1 has a life expectancy of 16.3 years, while Table 3 shows 26.5 years. Table 2 has a variety of figures depending on the spouse's age. Obviously, it's critical to use the right table.

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