Automakers have been trying different technologies and ideas in an effort to boost fuel economy and reduce emissions. On paper, the new technologies do make a difference. But in the real world, it is a completely different matter.
Emissions Analytics, an independent U.K.-based company has been investigating what technologies actually make a difference in reducing emissions and fuel consumption. For the past four years, the company has tested over 500 vehicles in the U.S. since 2013 in real-world driving situations. Globally, it has tested over 1,000 vehicles. Next month, the company will be releasing a study showing which of those technologies help and hurt.
"You can only decide if you have the right information. The EPA sticker is — I would say — good up to a point, but we can give a lot more information," said Nick Molden, Emissions Analytics' founder and CEO.
Their data shows that over four years of testing in the U.S., there is "no actual improvement in overall fuel economy and no decrease in CO2 emissions," despite new technologies and complex powertrains.
Vehicles with engines smaller than 2 liters have seen essentially no change in fuel economy; vehicles with engines 2 to 3 liters (the most common) have seen fuel economy decrease by around 8 percent, while vehicles with engines 3 liters or larger have seen an 8 percent increase in fuel economy.
This decrease among the most common vehicles is magnified in the U.S. because Americans are commuting longer distances without switching to smaller vehicles.
"If like-for-like the vehicles are not becoming cleaner, those other two shifts are actually going to drag up total CO2 emissions," Molden said.
EA's data also revealed that downsized turbo engines show huge discrepancies between the EPA's findings and the real world. In the lab, the engines aren't put under stress and can produce high fuel economy figures. But it is a different story out in the real world when the turbos are engaged to keep up with traffic and becomes less efficient than a non-turbocharged engine.
"Downsizing is a good thing up to a point. You go past a certain inflection point and actually you can find that the real-world mpg will actually get worse if you go too small," said Molden.
"As soon as you start going below 2 liters, that's where we start seeing the gaps open up between EPA sticker and real world."
The study did deliver some good news for hybrids. EA found traditional hybrid vehicle provided high fuel economy figures and reduced emissions. Other technologies such as multispeed transmissions, adding lightness, and picking the right tires provide a meaningful impact.
Source: Automotive News (Subscription Required)