According to multiple news agencies, drivers always complain that once they start driving their vehicles regularly, real-world mpg ratings fail to meet their expectations, which are usually supported by promising EPA ratings.

Experts decided to take a look at test procedures carried out by the Environmental Protection Agency and other factors to identify exactly what makes the ratings when it comes to real world driving so different from EPA ratings.

Recently, Hyundai had to roll back the fuel-efficiency claims related to some of its models after it was reported that the mpg ratings promised by the company did not meet real-world fuel economy ratings. The company itself linked this particular issue back to a South Korean crew test issue. This case was one of the many cases consumers find themselves wondering why their vehicle is not as fuel efficient as the EPA estimates.

Investigations show that several factors could be blamed for the discrepant results.

This issue was brought to light only two years after the agency received hundreds of complaints related to the problem. That was the time that took EPA to investigate the mpg claims properly. This issue allowed for several consumers to understand how the system works and see that the EPA does not really conduct fuel efficiency tests themselves but rather establishes the procedures that are then carried out by the companies.

When it comes to fuel efficiency testing, the EPA splits its results in two by offering ratings on city and highway driving estimates. When it comes to the combined estimates, the agency assumes that the average driver spends about 55 percent of his or her time driving in the city and about 45 percent of his or her time on the highway. This may create an overall estimate that does not meet real world expectations because most urban drivers, for an instance, spend most of their time driving in the city, and not much of it on the highway.

This can create discrepancies when it comes to the different ratings. City speeds cause the vehicle to be less efficient due to all the stops and aggressive acceleration. Highway driving makes for a much more conservative driving style thus a much higher mpg rating.

Other factors may also include individual driving styles, which could make the overall mpg ratings vary greatly. Motorists who adopt a much calmer driving style happen to get better mpg ratings than drivers who are more aggressive, even while on the road. Tests show that drivers who avoid attempting to perform unnecessary lane changes are likely to get better fuel economy than others.

Some other factors include air conditioner use, how big the vehicle is and what kind of weather the vehicle operates under, which could cause the vehicle to experience better or worse mpg results. Mountainous conditions, for an instance, could make vehicles less efficient.

For the full article and report, follow this link to read more.