What is the tax deduction for a hybrid car?

Hybrid car buyers are a step closer to finding out for sure how much of a tax credit they are eligible to receive under a new law.

The IRS has just issued guidelines establishing rules and a protocol for automakers to get their gasoline-electric hybrids certified as eligible for the credit.

Now it's up to automakers to submit the paperwork. The IRS will then grant or deny the credit.

The cleanest, gas-thriftiest vehicles will be eligible for a tax credit up to $3,400 off the bottom line of most buyers' tax bills.

Starting this month, the credit replaces a $2,000 tax deduction that wasn't as lucrative for most because it simply reduced a buyer's taxable income, rather than the tax bill directly.

"This is going to provide much-needed certainty to Americans who are purchasing these vehicles," Treasury Secretary John Snow announced in Detroit. "It means they will be able to rely on the manufacturer's certification when they claim the credit on their tax return."

Until their vehicles are certified, automakers are left to estimate:

• Ford. A Ford Escape or Mercury Mariner hybrid SUV buyer could get a $2,600 credit for two-wheel drive models and $1,950 for the four wheeler.

• Toyota. The tax credit could range from $2,200 to $3,150 depending on the hybrid that the buyer chooses — from its thrifty Prius to its big Highlander SUV.

• Honda. The new 2006 Civic will get an estimated maximum tax break of $2,100, the 2005 Accord hybrid (the '06 isn't out yet) will get up to $650 and the Insight automatic two-seater will be eligible for no more than $1,450.

"Now with these new credits, our customers can subtract directly from the money they owe the IRS. That makes the Escape hybrid and the Mercury Mariner hybrid even better values," says Christine Biondi, a Ford marketing manager.

Buyers can't wait too long, though. The law limits the number of hybrids that can receive the credit from a single maker.

Toyota is telling buyers that the tax credit could start being reduced on deliveries after June 30.