EPA MPG vs real world MPG clarified
 

Every day on this site I see countless posts by users complaining that the gas mileage their trucks are getting isn't matching what the window sticker rating stated the truck would get. There is also a lot of speculation about how the EPA tests, but I have heard only a few posts that actually convey the true testing procedure. I think a lot of the confusion surrounding the ratings is rooted in the lack of understanding regarding the testing procedures that the EPA mandates. These numbers aren't calculated by actually driving the truck around a track or on the road. There would be too many variables to have repeatable results that would have a uniform procedure for all cars.

The EPA gas mileage numbers are calculated through the following procedure by each individual company and randomly verified by the EPA:

Vehicles are driven on a dynamometer in a controlled laboratory setting (in order to eliminate weather and road variables). Both city and highway driving are simulated.

The city test is a 7.5 mile trip lasting 23 minutes with 18 stops, at an average of about 20mph. About 4 minutes are spent idling (as at a traffic light), and a short freeway segment is included. The vehicle begins the test after being parked overnight at about 72˚F.

The highway test is a 10 mile trip with an average speed of about 48mph. The test is initiated with a warm engine (following the city test), and is conducted with no stops and very little idling.

In 2008, the EPA also added three new tests. these included:
1) A high speed test (still only averaging 48.37 mph but now including a few short spans reaching 80mph.
2) an air conditioning test, where the ambient temperature around the vehicle is increased, the AC is turned on, and the vehicle averages 21.2mph.
3) A cold temperature test, where the vehicle is cold started in a lab that is 20˚F and driven an average of 21.2 mph.
graphs of each test can be located here

In the real world, one needs to factor in weight changes based on packages, wind, road surface, tires, gears, aerodynamics of different packages... the list goes on. All of these things change depending on the vehicle configuration you buy or the environment you drive in. It would be impossible for ford or any other company to test each package and give results accordingly (if you've used ford's online builder you know just how many combinations there are). Ultimately, the testing procedures should probably change to reflect a more realistic view of driving (mainly speed) but for now, I would just like to hopefully clear up how the results are actually obtained. Please feel free to add anything else you know as I am not the end all source on this subject! Hopefully this post will be informative to people and help to clear up some of the debate. In the end, people need to understand that the results from the EPA are not a guaranteed rating for real world driving and that it is unrealistic to expect to obtain them on a daily basis. Instead just go out and enjoy your awesome trucks and stop complaining about the numbers! :thumbsup:

Stickie?

Seems as though the calculations would include a factor for wind drag and rolling resistance.

Highway test with an average speed of 48mph? I feel as though MPG should be calculated according to the state in which the vehicle will be sold. Highway speeds here are usually 65-70 mph with the interstate being 75mph. I know speed limits are similar in other states but one is not always able to drive the speed limit which is probably why the average speed is 48 mph. Doesn't really matter I guess.

according to the EPA the dynos can have the resistance on the rollers adjusted to simulate drag but that doesn't really reflect the whole story. Picture the change in mpg you would see when looking at a 2wd XL regular cab short box and a 4x4 limited crew with a 6.5 box. Thats a pretty big difference considering reducing a car's weight by only 10 percent can improve fuel economy by 6 to 8 percent when everything else stays constant! ford does change the ratings on their site for the basic trim packages, but people still seem to expect the mpg of a stripped out xl in their top end trucks.

On my 2012 F150 Ecoboost, Highway Driving, I get as good as,10.4L/100km, 22.6 mile/us gal @ approx 60mph, Higher speeds 65- 70mph, or heavy loads, about 14 L/100km, 16.8 mi/us gal

2013 f150 screw ecoboost 3.55 gears 4x4
 

I get 17 city and 20 highway with light foot. Real driving i get between 15 city and 17 highway mpg.

On both of my vehicles, 2010 SHO and 2004 F150, I can get slightly better than the posted mileage for city and highway driving during the warm weather months. I drive cerefully but do exceed the posted speed limits slightly - so I am not that person doing 45 in a 60 zone. During the winter months the mileage drops considerably on both vehicles due to warm ups and the winter fuel blends.
Just a little bit of agressive driving in the warm weather and the mileage drops by several MPG. So, if you step on it to pass someone or to enjoy the sounds, you will not get to the posted mileage.

I can baby mine till the cows come home and not get close to sticker ratings. And I have tried.
Also my ecoboost isn't near as good as my 09 with the 5.4.

unless you have two trucks with the exact same body, engine and rear end gears you can't really compare mpg. add human factors and fuel blends the best you can hope for is to get within 25% what is on the sticker. remember nobody ever said "wow I'm getting too good gas mileage. I wonder what wrong" lol