Why is the federal tax credit for a HAH so low? I mean come on, $650 for a HAH versus $3,150 for a Prius?

I believe it depends on the vehicle's emission rating. A 6 cyl is not as clean as a 4 cyl. I may be wrong???

Nope. It's based on level of FE improvement:

http://go.ucsusa.org/hybridcenter/incentives.cfm

Federal Tax Credits for Advanced Vehicles: On August 8, President Bush signed the comprehensive energy bill into law. Included were new tax credits for advanced vehicle technologies ranging from $250 to $3,400 depending on the vehicle's level of fuel economy improvement. For a limited time, quality hybrids like the Honda Civic Hybrid, Toyota Prius or Ford Escape Hybrid will qualify for tax credits in the range of $1,700-$3,150. The tax credits will be available beginning on January 1, 2006 and will be available through December 31, 2010, though they will expire earlier for the most popular hybrids. The full tax credits will be available until a manufacturer reaches 60,000 vehicles sold (60,000 for Toyota, 60,000 for Ford, etc.). Once a manufacturer has sold 60,000 vehicles, a one-year "phase out" will begin after the next complete calendar quarter; 50% of the credit will be available for that manufacturer's hybrids in the first two quarters of the phaseout period and 25% in the final two quarters. UCS estimates the following credits for each hybrid vehicle currently sold:

HEV Model Emissions Rating Tax Credit
2005-2006 Toyota Prius Bin 3 $3,150
2005 Honda Insight (automatic) Bin 5 $1,450
2005 Honda Insight (manual) Bin 9 $0
2005 Honda Civic Hybrid (automatic) Bin 2 $1,700
2005 Honda Civic Hybrid (manual 5-speed) Bin 2 $1,700
2005 Honda Civic Hybrid (lean burn, automatic) Bin 9 $0
2005 Honda Civic Hybrid (lean burn, manual 5-speed) Bin 9 $0
2006 Honda Civic Hybrid Bin 2 $2,100
2005 Honda Accord Hybrid Bin 5 $650
2005 Ford Escape Hybrid (front wheel drive) Bin 4 $2,600
2005 Ford Escape Hybrid (four wheel drive) Bin 4 $1,950
2006 Mercury Mariner Hybrid (four wheel drive) Bin 5 $1,950
2006 Toyota Highlander Hybrid (front wheel drive) Bin 3 $1,950
2006 Toyota Highlander Hybrid (four wheel drive) Bin 3 $2,200
2006 Lexus RX-400h (four wheel drive) Bin 3 $2,200

Thanks to the posters in http://www.greenhybrid.com/discuss/2...tics.5129.html for finding this.

Change what & how I drive, not who I am. Rack 'em up.

FE improvement in that particular "inertia class" as used for the EPA testing. Basically curb weight + type of vehicle. The FE improvement of the HAH over the rest of that size/weight class is not as much as the improvement for the Prius versus its class.

Counterintiutive, as much of what comes out of the funny looking white domed building is.

The system for the rebates compares the EPA estimate of the vehicle to the average for all 2002 vehicles of the same weight class. The HAH, designed for performance rather than efficiency, gets a relatively small rebate. Other hybrids, with their higher EPA ratings, get closer to the maximum of $3400.I don't believe that emissions have anything to do with it.