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Here's Why Real-World MPG Doesn't Match EPA Ratings

Edmunds.comEdmunds.com Member, Administrator, Moderator Posts: 10,315
edited September 2014 in General

imageHere's Why Real-World MPG Doesn't Match EPA Ratings

EPA fuel-efficiency ratings often don't match real-world fuel economy performance. Here's why.

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Comments

  • bpizzutibpizzuti Member Posts: 2,743
    The bottom line is that some 40 MPG cars actually seem to get 40 MPGs, and others don't. Either they've already figured out how to game the most recent EPA tests, or the car manufacturers are simply providing fake numbers. The EPA really needs to verify the manufacturer numbers when few people seem to match them.

    Regarding Hyundai, they've been caught before on publishing inaccurate numbers: anyone remember when they had to revise the power figures on their engines?
  • 34pete34pete Member Posts: 4
    These guys game the EPA numbers by programming the automatic transmissions..often keeping underpowered cars in high gears.. IRL people get frustrated and push on the pedal more..

    This is why IRL standards seem to beat automatics in all but fairly powerful cars.
  • 34pete34pete Member Posts: 4
    The EPA does test the cars - you can't fake the numbers.. You can game them though with underpowered engines and cheezy quick to upshift automatics.
  • xqqqqmexqqqqme Member Posts: 1
    When are consumers (and, for that matter, auto journalists) going to realize that the EPA mileage ratings are NOT -- and never have been -- predictions, promises, or contractual obligations. They are ratings by which you can COMPARE two or more cars in the same category. If you are shopping for a car and are looking at two, the first with a 34 combined rating and the other with a 28 combined, it doesn't matter that you might not get any better than 30 mpg when you actually drove the first vehicle with your habits and routes. But what you COULD conclude -- and prior to purchase -- is that no matter how you drive, car #1 would give you better mileage than car #2. And that's what the EPA ratings are for.
  • litesong2litesong2 Member Posts: 44
    The EPA uses 100% gasoline(no 10% ethanol blends) to obtain their mpg ratings for all gasoline vehicles sold in America. Switching to 100% pure gasoline, our 3 cars increased their mpg by 8%, 7-8% & 6%. Go to pure-gas.org for the 4800+ stations selling 100% pure gas in the U.S. & Canada. Some stations charge a lot for their gas, but some have good prices.
  • sanschusanschu Member Posts: 1
    I got dooped into buying an Elantra. I turned in a Saturn SL2 1996 that got 27 to 32 miles to the gallon on average. Which is pretty much what the sticker said when I bought it. My Elantra is averaging 24 to 33 miles to the gallon depending on traffic. The same traffic and route used by the Saturn. This is where I am miffed to spend 20K (they charge a premium to get the car) to have essentially the same car. I would have been better off continuing to repair my Saturn.

    Low speeds seem to be the problem. I can watch the average MPG drop while sitting at a 5 minute light.
  • steveieboysteveieboy Member Posts: 1
    I move cars, all makes and models, for local dealers and always get better MPG than the EPA estimates. I drive using cruise control and rarely exceed the posted speed. Ford products may be the exception as I've gotten over 40 MPG on Fusion SE's, but never better than 19 MPG on any F150's. I can't comment on in-town driving as I do so little of that with these cars. I only touch the brake when it must be touched to avoid a collision. Slow starts and slower stops will increase your MPG by more than you'd think.
  • webefastwebefast Member Posts: 2
    Thank you xqqqqme for your comment, it is spot on. Far too many people seem unable to grasp this basic fact. The recent work done by Greene and Lin at ORNL confirms what was reported by Patrick Bedard column "Lousy Mileage? Is it Your car, or Your foot?" in the Feb 2006 issue of Car and Driver magazine.
  • bertmetbertmet Member Posts: 1
    You need to follow 1000 new cars and ask then drivers to record miles driven and gas purchased. Report these figures. Then the buyer will know what to expect.
  • frenifreni Member Posts: 2
    2013 - Ford Escape Ecoboost 2.0 - my new Ecoboost is performing way below expected mileage. Max 20.5 (highway only) 15.9 (city only) are others having the same experience. I should mention that I only have 1000 miles so far. Very disappointing performance so far in an otherwise desirable package.
  • delo13delo13 Member Posts: 1
    steve IDK about F150's but I have Ranger, my model rated at 14/16/18. I get 18 on average and I am a fairly aggressive driver with heavy feet. I would think if I absolutly tried I could get 19 or 20 consitantly.
  • wikkidwikkid Member Posts: 1
    "Crawling toward Manhattan on the Staten Island Expressway" uhhh, really? Check the map next time(I hear Google has some real nice ones.) The only way to go from Staten Island to Manhattan is the ferry, passenger only ferry. Otherwise you'd have to either crawl through Brooklyn first, or through New Jersey.
  • zedozedo Member Posts: 2
    The technology for extremely high mileage cars already does exist. In fact, its readily available in Europe, and has been for years, its just not sold in the US. Additionally, the king of green cars right now is the good old Ford Fiesta. The same exact model that you can buy now in the US, except with a greener engine on the European model. When many consumers asked Ford why this Ford Fiesta Zetec Econetic 1.6 TDCi option was not available in the US market, they were quoted as saying, "We are afraid it wont sell in the US". Oh yeah, nobody here wants 70+ MPG, pfff. Additionally, in the Euro circuit, ford claims that this green Fiesta is the hottest selling car in Ford history...go figure.

    http://www.totallymotor.co.uk/new-car-news/2012/05/10/ford-fiesta-econetic-1-6-tdci-95ps-first-test-drive-review

    http://www.nextgreencar.com/view-car/43016/FORD-Fiesta-1.6-Duratorq-TDCi-Edge-Econetic-95PS-DPF-Diesel-Manual
  • zedozedo Member Posts: 2
    FYI: Another car the US will never see that's going into production in Europe. 261MPG!

    http://www.caranddriver.com/reviews/volkswagen-xl1-concept-first-drive-review
  • blacktigerblacktiger Member Posts: 8
    See the results of my continuing experiment on "Kia Forte Real World MPG"
  • dowzerdowzer Member Posts: 1
    edited April 2015
    I have owned a 2001 Lincoln Continental, 2007 Nissan Murano, 2010 Mazda CX-7, and now a 2012 Mercedes C300 4matic. While owning these past four vehicles, I have been successful at exceeding the "Highway" mileage while driving my mixed driving. I probably do 60-65 highway but that can be slow and go to and from work. I drive reasonably by honoring the speed limit (most of the time), knowing where the slow-downs are going to be and slowing earlier, and not jumping off the line. BUT by far, the biggest thing I have done is use the cruise control A LOT. My current vehicle said that the "combined" mileage is 20 mpg and the worst I have gotten in the 2 months that I've owned it is 20.7. I've gotten as high as 28.2 and am averaging 25.2. I am not a "hyper miler" but a 40 something guy who just learned that I could save money by not acting like a 20 year old.
  • apm_designsapm_designs Member Posts: 1
    Been reading all these comments and they are interesting indeed. I am writing in rest of the NEDC (I guess Europe's equivalent to the EPA.
    I am not too sure about how the EPA operate, but I have read somewhere that manufacturers tend to get prototype vehicles tested out that are set up for max efficiency which are not exactly the same as the car they sell to public. Having said that the NEDC is completely outdated and has so many loop holes that it could be entirely likely that a car that has been recorded with a high MPG could in fact be less efficient that one with a lower MPG.
    What shocked me was the following which each manufacturer was allowed to do....basically there is no fair playing field:

    1) Reaching 70 mph for only 10 secs. Giving cars that have good MPG at higher speeds a disadvantage
    2) Removing body parts likes roof rack and driver mirror. Manufactures who decided not to do this are in a disadvantage
    3) Tyre pressure, manufacturers are allowed to over inflate their tyres reducing roll resistance and increased efficiency.

    I do not want to bore with more details, but there is more on this article I was reading www.automotive-hub.blogspot.com.....and honestly it would be interesting to see how this compares to the EPA.
  • steverstever Guest Posts: 52,454
    edited July 2015
    There are too many variables to say that you are going to get the EPA numbers in your car.

    @xqqqqme said it best - "They are ratings by which you can COMPARE two or more cars in the same category."
  • texasestexases Member Posts: 10,685
    Let's say the EPA estimates were exactly right, on average. That means that about half the people would get worse, half better. There's no way a single set of estimates will ever be more than that, an estimate. For all, or most people to get the EPA #s means the EPA estimates would have to be unrealistically low.
  • tdw1954tdw1954 Member Posts: 8
    Anyone can go to Fuelly.com and see what real world mileage people actually get for any year, make, model and powertrain combination. There you will see that the highest rated SUV in it's class, the Chevrolet Equinox, actually gets the worst mileage of any of it's competition. Anybody claiming they can achieve the EPA highway MPG on anything they drive has never driven a 4 cylinder Equinox.

    The one thing that would improve the accuracy of the estimates is to fine manufacturers when the car will not achieve the claimed MPG. EPA could do testing when they get complaints. It's clear that some manufacturers are gaming the test similar to how VW gamed the emissions test.
  • energyfollowerenergyfollower Member Posts: 1
    @texases - what you've described is a median value, not an "average" at all - which is referred to as the "mean". It is very easy for an average to have far more on one side of it than on the other.
  • texasestexases Member Posts: 10,685
    Ah, the statistics pedant appears...
  • MDB007MDB007 Member Posts: 1
    Every car and driver is different but I found something interesting. I bought a 2012 Acura TL in 2018 and it gets worse gas mileage under 65mph, around 25mpg. The sweet spot on a trip with cruise is between 65-70mph i get on my weekly drive to work about 26mpg but on a highway trip will hit 28mpg. So feel they have the computer set up to work with 6 speed tranny to deliver the best results at those speeds which are more real world than 55mph the govt has mandated forever.
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