True, the battery pack and associated hybrid equipment means the model will weigh more. The Accord hybrid's curb weight is 3,589 pounds as compared to the regular EX V-6's 3,437 pounds. The hybrid Accord comes with a 3.0L V-6, an engine available in non-hybrid form too. The non-hybrid makes 244hp at 6,250 rpm, while the hybrid makes 253hp at 6,000 rpm. The non-hybrid makes 211lb-ft of torque at 5,000 rpm; the hybrid is 232lb-ft at 5,000 rpm. The non's compression ratio is 10.0:1. The hybrid's is 10.5:1. The Dodge Ram HEV features the Cummins 5.9L turbodiesel and puts out the same beefy 325hp and 600lb-ft of torque as the non-hybrid, despite a 600-pound curb-weight difference. Performance doesn't have to suffer, as you can see.
The window sticker is not a prediction. Rather, it is an average value. EPA testing does not include the use of any accessories in the process -- like the air conditioning -- or aggressive driving. Information for the fuel-economy data (and emissions) is not gathered from behind the wheel but in a laboratory, simulating real-world conditions. The EPA admits that particular real world was 20 years ago (the last time it changed the estimate calculation method was in 1985), but by the time you read this, the organization should have drafted a proposal for updating fuel-economy estimates and the testing procedure.
Think of it this way. An '06 Jeep TJ with a four-banger and manual tranny should be getting 18 mpg in the city and 21 on the highway, according to the EPA estimate. But take a small engine and turn on the air conditioning or defroster, then drive up a steep grade, and that's a greater percentage of power the engine has to find to get you up the hill and keep you cool. Therefore, it'll burn more gas/energy. Ditto the hybrid. Put it in the same scenario as the TJ and you can understand why its fuel economy may not be what was generated for the sticker. Also consider this, the percentage difference in fuel economy between a hybrid's sticker and the real world really isn't different from a conventional engine and its true mpg.
It's not bogus -- a hybrid can get the fuel economy claimed, just like a regular vehicle can. But it has a lot to do with driving habits (rapid acceleration, slamming on the brakes), plus loading the vehicle to the gills with junk and really fat guys, cold weather, low tire pressure, and so on. Speed is another issue. Where hybrids really perform best is in the city, at low speeds, and especially in traffic. The engine shuts off during idle (which saves gas and doesn't put out emissions like a regular car and truck), causing the vehicle essentially to rest, with the accessories and auxiliary systems handled electrically by the battery. But on the highway (or anytime you're traveling above 40 mph), the power comes primarily from the engine, which then works with the electric motor for hard acceleration, such as lane changes. Emissions: The Bigger DealWe mentioned earlier that the EPA regulates vehicle pollution (greenhouse emissions); technically, it counts the amount of hydrocarbons, carbon monoxides, and nitrogen oxides in the exhaust. Therefore, the idea behind hybrid technology is not just about the fuel economy but also the reduction in emissions. Hybrids can emit up to 90 percent less waste than a conventional engine. For example, using the EPA's scale of 15.3 tons for worst and 3.1 tons for best, the Prius is rated at 3.5 tons and the manual-tranny Insight is 3.1 tons. For perspective, the Jeep Commander and Grand Cherokee with the Hemi come in at 11.7 tons, the diesel Liberty is 9.1 tons, and the Wrangler with the 4.0L six-cylinder is 11.6 tons. That much from the little, lightweight Wrangler? That could be pointed to an engine design that's old and less efficient (call that information a premonition of things to come), and it's inside of a vehicle that isn't exactly known for its wind resistance or low drag coefficients (big tires and brakes). Couple those vehicles with, say, the Ford Expedition four-by with the 5.4L V-8 (12.4 tons), the Porsche Cayenne Turbo (12.6 tons), or even the Lamborghini L-147/148 Murcielago with the 6.2L and stick trans (17.7 tons), and you can see why the government is on the automakers' backs to clean up vehicles. There is no argument that hybrids are cleaner and better for the environment than anything out there. Plus, the battery pack is recyclable.