Here's Why Real-World MPG Doesn't Match EPA Ratings
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Here'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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Regarding Hyundai, they've been caught before on publishing inaccurate numbers: anyone remember when they had to revise the power figures on their engines?
This is why IRL standards seem to beat automatics in all but fairly powerful cars.
Low speeds seem to be the problem. I can watch the average MPG drop while sitting at a 5 minute light.
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
http://www.caranddriver.com/reviews/volkswagen-xl1-concept-first-drive-review
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 Having said that the NEDC is completely outdated and has so many loop holes that it could be entirely likely that a car that has been recorded with a high MPG could in fact be less efficient that one with a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.
@xqqqqme said it best - "They are ratings by which you can COMPARE two or more cars in the same category."
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.