Washington ? New rules for donating that old car, tax breaks for hurricane victims and people who helped them, and bigger incentives to save for retirement are among changes Americans will see this tax-filing season.

Other new wrinkles include: High gasoline prices lifted the standard mileage rate allowed for business use of vehicles. And a new definition of “qualifying child” affects tax benefits for certain filers – the technical details of which might make your eyes glaze over.

But if the fine print is too much to take, take heart: This year, the Internal Revenue Service has made it easier to procrastinate. The filing deadline is April 17, two days later than usual because the regular deadline, April 15, is a Saturday. And there’s a new, automatic six-month extension anyone can get by simply filing a form.

Also, the IRS Web site features new online tools for figuring qualification for two complex tax items – the alternative minimum tax and earned income tax credit – as the agency continues to prod taxpayers toward electronic tax preparation and filing.

“Electronic filing is a quick, easy, smart way to file your taxes and get your refund faster,” said Richard Morgante, commissioner of IRS’ wage and investment division, which handles taxes filed by individuals.

Last year, 68.5 million individual returns were filed electronically – more than half, and an 11.3 percent increase from the previous year. Many were e-filed by tax professionals, but about 17 million came directly from home computers. Safeguards ensure e-filing is secure, the IRS says.

Those still resisting that route should know this: Taxpayers who e-file and have refunds deposited directly into their bank accounts get the money in as few as 10 days, compared with six to eight weeks to get a refund check when paper tax forms are filed by mail.

Congress added several temporary tax breaks for victims of the devastating hurricanes Katrina, Wilma and Rita. Some highlights:

¢ Suspension of limits on writing off personal casualty losses; normally, such losses must be reduced by a $100 deductible and by 10 percent of the taxpayer’s adjusted gross income.

¢ Option to use 2004 income to figure the 2005 earned income credit and refundable child tax credit; for many hurricane victims, this will result in those credits being larger.

¢ Waiver of 10 percent penalty for early withdrawals from Individual Retirement Accounts and other qualified 401(k)s for people whose principal residence was in the disaster area.

Tax breaks for people who helped hurricane victims include:

¢ Increase in mileage deduction for vehicles used in volunteer work to help hurricane victims (29 cents a mile for vehicles used between Aug. 25-31, 34 cents a mile from Sept. 1-Dec. 31).

¢ Additional $500 exemption ($2,000 household maximum) for taxpayers who housed hurricane victims for 60 continuous days.

¢ Increased deduction for cash contributions to qualified charities – from 50 percent to 100 percent of adjusted gross income for donations made between Aug. 28 and Jan. 1. The money didn’t have to be earmarked for hurricane aid.

Other changes for 2006 include new restrictions for charitable deductions of cars worth more than $500, a deduction long abused. Many taxpayers claimed the fair market value of the car based on used-car value guides available at banks and car dealers, even if the car was a non-running junker worthy only of the scrap heap.

Now, taxpayers can’t deduct more than the charity collected by selling the vehicle, except when the charity sold the car to a needy individual or family at a steeply discounted price. A written acknowledgment from the qualified charity must be attached to the donor’s tax return and it must say how much the car sold for.

There’s also a new uniform definition for “qualifying child,” which is used for the dependency exemption, head of household filing status, earned income tax credit for lower- and moderate-income working individuals and families, child tax credit, and credit for child and dependent care expenses.

This standardized definition was designed to reduce confusion that sometimes resulted in multiple taxpayers claiming credits and exemptions for the same child. The IRS has devised several “tests” that determine who gets to claim the child, based on the child’s age, relationship to the taxpayer, length of time living with the taxpayer and amount of financial support the child provides. The tests vary with the tax benefit claimed.

Also for 2006, the IRS adjusted the standard mileage to reflect 2005’s increases in the price of gasoline. For business use of vehicles from Jan. 1 to Aug. 31, 2005, the standard mileage rate is 40.5 cents per mile, compared with 37.5 cents a mile in 2004. Beginning on Sept. 1, 2005, the rate rose to 48.5 cents.

Ceilings for tax-deferred contributions to traditional IRAs have risen from $3,000 to $4,000 for most savers and from $3,500 to $4,500 for those age 50 and older, within certain income restrictions. Ceilings on Roth IRA contributions – which are taxed, although later distributions from the Roth aren’t – also increased.

The IRS also made inflation adjustments for other credits, deductions and tax categories. For example: Each personal and dependency exemption rose to $3,200, up $100 from 2004. The standard deduction is $10,000 for married couples filing a joint return and qualifying widow(er)s, up $300; $5,000 for singles and married individuals filing separately, up $150; and $7,300 for heads of households, up $150.

And the IRS has streamlined state sales tax tables for itemizing taxpayers who choose to take the deduction for state and local sales taxes rather than the deduction for state and local income taxes.

At the IRS Web site, www.irs.gov, taxpayers can get answers to many tax questions, download and print tax forms, track refunds and find links for free electronic filing and hurricane-related tax assistance. The IRS tax information line is (800) 829-1040 for individuals and (800) 829-4933 for businesses.