Environmental concerns and rising gas prices have fueled the recent boom in hybrid cars. But the initial excitement has been tempered by lower-than-advertised gas mileage. Across the Internet, hybrid enthusiasts are complaining in forums and blog testimonials about the mileage they aren’t saving. Pete Blackshaw of Cincinnati posts a blog (http://hybridbuzz.blogspot.com/) regularly to educate hybrid owners on how he is handling his Honda Civic Hybrid complaints. Although tests conducted by the Environmental Protection Agency (EPA) averaged the Civic Hybrid at 47 mpg, Blackshaw said he is averaging only 32-33 mpg. Fueling his frustration are the vague responses he has received from both Honda and Congress. “This blog has shifted from high-octave ‘love letter’ to dispirited ‘tough critic’ because I fear there's a troubling and well-documented gap between the brand ‘promise’ – reflected in Hybrid advertising, promotion, and dealer representations – and the actual product ‘benefit’ and performance,” Blackshaw says in the blog. Blackshaw’s concerns are echoed by numerous others who own either a Toyota Prius or a Civic Hybrid of their own. In a recent study, Consumer Reports also found that the Prius is averaging less than what EPA suggests – a mere 44 mpg compared to the 55 mpg (highway and city average) touted by EPA. But Toyota and Honda reps argue that they have not misled hybrid customers at all. “It’s important to realize that the EPA estimate is exactly that – it’s an estimate,” said Chris Naughton, spokesman for Honda. “EPA estimates are an excellent means of comparing fuel economy figures for vehicles within a competitive set because they’ve all been tested with the exact same test procedure making for a valid comparison.” Toyota spokeswoman Nancy Hubbell agrees. “The numbers that we put on the car, and the numbers that we use, are the numbers we have to use, and certainly we try to explain to the customers the numbers are not what they’re likely to get on the road,” she said. Honda also gives out owner’s manuals that instructs drivers on how to better their mileage. Naughton said it’s not realistic to tell customers they will always achieve the stated mileage. He said avoiding jackrabbit starts, adhering to the upshift light and using the air conditioning sparingly could help maximize mileage. “Just drive the car at a normal rate of acceleration,” Naughton suggested. “Don’t accelerate too quickly because that lowers fuel economy quite a bit, and also use light braking when it is safe to do so. Light braking doesn’t engage the mechanical brakes as much. It instead takes advantage of regenerative braking – keeping the battery pack full of electrical energy.” Toyota supplied Business Fleet with an informational package given to sales consultants dealing with hybrid customers. According to the package, weather, tire pressure, terrain and vehicle load will affect fuel economy, and “for these reasons, Prius drivers may not achieve the EPA estimates in real-world driving – just as other drivers may not achieve their car’s EPA-estimated fuel economy," the packet notes. "And, compared to other midsize cars, Prius is capable of achieving truly impressive and superior fuel economy.” This is proven by the growing waiting list for incoming Priuses, Hubbell says. John DiPietro, road-test editor of Edmunds.com, said he was impressed with the Prius he drove for nearly 1,000 miles in 10 days to visit family. Over the course of highway and city driving, DiPietro says he averaged 48 mpg – over 86 percent of EPA’s all-around average of 55.5 mpg. “That’s simply impressive for a car that offers nearly the room, comfort and performance of a four-cylinder Camry,” he said. However, DiPietro admitted that the EPA testing process, although fairly comprehensive, still doesn’t take several real-world driving conditions into account. City testing involves an 11 mile trip with 23 stops at 20 mph to simulate traffic, but cold temperatures and even city conditions, where drivers tend to be heaviest on the gas, are not part of the test’s considerations. The highway portion involves a 10-mile run with no stops at an average speed of 48 mph and a maximum of 60 mph. “Most Americans tend to have lead feet, which obviously doesn’t do much for fuel economy,” DiPietro admitted. “We all know that people drive much faster than that on the freeway, and higher speed brings more aerodynamic resistance, which brings down fuel economy.” The EPA has recently agreed to review how it calculates fuel economy. Environmental groups have complained for years that actual miles-per-gallon can be as much as 34 percent lower than posted fuel economy ratings. The current test, established nearly 30 years ago, does not reflect current crowded highway conditions, higher speed limits and air-conditioning usage. The EPA is seeking comments from drivers, manufacturers and others about real-world driving experiences. The comments period ends July 27.