Factors that go into rating a car's fuel economy?

The EPA requires tests cars for mpg on a virtual "course" using dynamometers to add load. During the runs on the pre-programmed course, the car is loaded up with tons of measuring instruments to get data on fuel consumption, emmissions, and tons of other info.

All cars are testing using automated procedures, so things like driver technique, fuel quality, routes, and weather are controlled and eliminated as factors.

The EPA mileage estimates don't always translate directly to our day-to-day driving, but the are very useful as comparisons between different cars.

In general, cars are made and geared for best efficiency in the 55-65 range. Going too far above 68 or so will usually cut your efficiency.

See here for more information direct from the EPA:

http://www.fueleconomy.gov/feg/how_tested.shtml

car mfg.. to test their fuel economy drive at the speed of 35

I have read the EPA test is from 55 to 65 use25%more fuel and

65 to 75 uses 25% more fuel but that seems to much more fuel

when testing tire pressure is a factor weight is also, useing

cruse control tuned up engine I believe that 60 miles per hour

would be a good speed for fuel economy

Lies, poverty and the ever lowering life-style of average Americans is what most get from the trickle-down theory. Most of my work is in the largest, self-contained retirement community in the U.S., it's called The Villages and located in central Florida. I wouldn't call these people super wealthy but I'm sure many of them can be called millionaires. These are the people who fought in the second world war and returned to America to go to work for General Electric, Ford, GM, Westinghouse, RCA, etc. The fifties, where one in three workers in America belonged to a union. Life was good, companies were strong and people made a good living. Somewhere along the line of this ideal situation where everyone was making money, somebody or a group of somebodies decided they weren't making enough and the slow destruction of the middle-class was started and it has quickened over the years to what we have now. It's the decisions of those in power, many of which are from corporate America who later become politicians who then pass legislation to further channel the wealth of America to a select group in big business, with the lie of trickle down attached. There is no such thing as free market, it's all manipulated, condensed through mergers strangling competition and giving business an iron fist to contol their own destiny at the expense of the everyday worker. Throw in millions of illegals taking the lower paying jobs in America and the workers who earn the least suffer the most. To me trickle down means the more those at the top can keep, the less trickles down. For those old enough who can look back at the fifties, can you honestly say trickle down economics has made this country better today than it was then?