"real World" Fuel Economy Vs. Epa Estimates

Consumers have a tendency to assume that the big black numbers on a automobile window sticker, the one that shows the EPA estimated fuel economy rating, are what they will ultimately get while driving that vehicle. Sadly, this is another situation that fits under the heading of, "Read the fine print." The fine print actually states, in its intent, actual performance may vary based on many factors.
What you as a car shopper should be aware of is that the MPG you get could be less. A lot less.
Factually a lot of time and expertise goes into testing for fuel performance. And these numbers that they come up with are a good source of important data when you are comparing two candidates for your next purchase. What is missed by many though is that, as part of the test program a number of assumptions are made about driving habits. Those assumptions have not been updated recently; hence the discrepancy.

New cars are tested by the manufacturer according to guidelines laid out by the EPA. The EPA in turn reviews that data and verifies 10% of the test results with their own testing. The vehicles are tested by placing the drive wheels on a "dynamometer," a machine that allows the testers to do driving simulations while the vehicle is actually not moving. The vehicle is tested based upon to two different "schedules" to produce the city and highway rating results posted on an automobile's window sticker. (Fuel economy ratings are also included on the "Specs" page of all the vehicles on Edmunds.com.) The two schedules attempt to represent different styles of driving that might be encountered in the two types of driving:

City: The test begins with the vehicle’s engine cold. The car then is run in such a pattern as to replicate eleven miles of stop-and-go rush-hour traffic. Periods of idling are part of the patterns in the test; average speed is twenty mph and the highest speed is 56 mph.

Highway: This test approximates 10 miles of a mixture of rural and interstate highway driving. The car is already warm before the test begins and the average test speed is about 48 MPH. The highest speed reached is 60 mph. No intermediate stops or idling are included in the test.

The EPA admits that tests and real life driving might differ. It prescribes the difference to — among other things — the fact that the test cars are in optimal mechanical condition and thus will do better. But by looking at the EPA's testing process, it is clear that the routines of today's drivers are not duplicated. On most highways, speeds of well over 60 mph are common resulting in considerably lower fuel economy ratings. Similarly, although the EPA tried to parallel city conditions by introducing periods of idling, today's overly congested roads produce considerably more and longer prolonged stops.

Article Source: http://www.search4allinfo.com

Activist, consumer advocate, entrepreneur and activist, GARKO, shows you how to increase power and save gas and how to run a car on hydrogen from water which is the best of the ways to save big on gas For a list of current gas prices in your neighborhood email garko@startlingdiscoveries.info

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