How the EPA gets there - Lincoln MKZ Forum
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post #1 of 3 (permalink) Old 07-22-2013, 01:40 PM Thread Starter
zep
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How the EPA gets there

With all the hubbub lately about falsified mpg claims and lawsuits pertaining to MKZ hybrids and other Ford/Lincoln offerings I thought it would be a good time to check in on how the EPA comes up with the mileage figures we all weigh so heavily into our purchase decisions, have a look:

• In a lab the drive wheels are pulled onto a dyno to simulate driving dynamics.
• Driver runs the car through a standardized driving routine attempting to simulate real world trips.
• A schedule stipulates the speed the car must travel at during every second of testing
• An outlet hose captures exhaust gases and measures them to calculate the amount of fuel consumed.

Things to keep in mind:

• Outlet hose measurement cannot effectively capture mileage estimates for Fuel cell, electric or hybrid vehicles
• No idle time that simulates red light fuel waste
• Vehicles are babied, light acceleration and diminished speeds ( about 50 mph for highway test)
• City test lasts 5 minutes, Highway test lasts 12 minutes
• City test done with cold engines, Highway test done with warm engines

Looking at this list its very easy to see where gaps in mileage claims come from...
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post #2 of 3 (permalink) Old 07-23-2013, 02:45 PM
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And even with this mentioned making it seem as if the EPA does things properly, which they probably pass themselves off as doing so, we still get cars with EPA numbers that are no where close to what mass amounts of consumers are getting with their real world numbers.



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post #3 of 3 (permalink) Old 07-23-2013, 02:56 PM Thread Starter
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Originally Posted by MKZFan View Post
And even with this mentioned making it seem as if the EPA does things properly, which they probably pass themselves off as doing so, we still get cars with EPA numbers that are no where close to what mass amounts of consumers are getting with their real world numbers.
That is no way an endorsement of EPA protocol, its outlined as such to highlight the sheer absurdities. 12 minutes on a dyno at 50 miles per DOES NOT effectively measure highway fuel consumption.

Additionally, the EPA was originally set up to measure emissions not fuel consumption. Theres a list floating around with the worst EPA mileage gaps and like 80% of the list are Hybrid vehicles...
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