Apparently, the EPA or whoever does it is now going to rate fuel economy based on different criteria than before. Accordingly, some cars will be downgraded by about
20% in terms of what their current fuel economy ratings are. However, this could also result in FE ratings for hybrids dropping by 30%. I'm surprised owners haven't noticed the disparity already.
They have, and there has been much public discussion about it, since they hit the market.
EPA Fuel Economy Ratings Have Shortfalls Of Up To 50 Percent Window Stickers Vastly Overstate MPG, Consumer Reports Study Finds September 14, 2005
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The Truth About Fuel Economy Ratings
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9/6/04 The lie of the needle Like many new owners of the Toyota Prius, Margo Oge noticed something surprising once she began driving her new car last winter: Her gas mileage was well below the numbers listed on the sticker.
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The Jeep Liberty Diesel 4WD, rated at 22 mpg in the city by EPA, got 11 mpg in the test. The Honda Civic Hybrid Sedan, rated at 48 mpg in the city, could manage only 26 -- a 46 percent lower rating.
Other outlets also have found considerable discrepancies in mileage figures. AAA, which has called for a change in EPA fuel economy standards, tested a number of 2003 and 2004 models and found that a 2003 Chrysler PT Cruiser, rated at 20 city/26 highway by the EPA, could only achieve 17.5 mpg.
Current methods used by the EPA assume drivers won't go over 56 mph in the city and 60 mph on the highway, and that drivers won't accelerate by more than 3.3 miles per second.
Critics say current EPA tests don't capture time spent idling in traffic; they say many cars spend almost two-thirds of their time in stop-and-go traffic. EPA also doesn't turn on their air conditioning when testing cars or take into account newer accessories that affect mileage. The agency also tests hand-built prototypes provided by the manufacturers.
The EPA tests don't have to have a number that matches rear world conditions. Odds are whatever test they come up with won't match.
The test has to be the same for all vehicles. That way one can compare car A to car B. That's all the number is good for and all it will ever be good for.
Maybe things have changed. My cars, even my SVO, where the accelerator only had two positions: idle at light or stop sign, and go-like-hell, pretty much lived up to their various EPA stickers.
Fortunately, there was almost ALWAYS a fair amount of highway miles.
Recently though my wife complained that her Taurus' mileage was dropping way down. A little investigation brought out the total number of break- minutes she spent in the parking lot with engine running... have to remind her every cold and hot season.
The last 3 vehicles I have bought new were dead on the snooter for the milage rating. The used Mustang gets more than rated. THe Nissan truck gets more than rated after a new exhaust, air breather and synthetic oil.
I can't speak for hybrids since I don't own one. However, my '06 V6 got 25 highway the last time I filled it up and the sticker says 28. If I didn't have the defroster on, the AC wouldn't have been running and the mileage would have been higher. Of course, about 45 of the 250 miles I drove the car were city miles, so that would affect it as well.
To give another example, my Saturn SL gets 45 in pure highway driving. I don't know what the sticker rating is, but I'm not about to complain about having one of the cheapest daily drivers on the road that isn't a hybrid. It's just pure physics with that car - small engine, crappy hp, light weight, no accessories.
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