Environmental Impact Of Direct Injection Engines

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While gasoline direct injection engines are known for improving a car’s fuel efficiency, low emission levels in certain situations, and providing enhanced performances, there are a couple of downsides that make them far from perfect. For one thing, they cost a lot of money to build – as much as 5 percent more than other, regular engines, according to some estimates. Additionally, they can generate larger amounts of nitrogen oxides, which are significant air pollutants. This is why there is an ongoing debate over how effective and valuable direct injection engines truly are compared to other engines. This debate was further fueled by a recent study, according to which, new gasoline direct injection (GDI) engines are even more harmful to the environment than older engines.

The study was commissioned by the European Federation for Transport and Environment, an environment lobby group with headquarters in Brussels. It was conducted by TUEV Nord Group, an independent agency that provides inspection, testing, and certification services, based in Germany. Results of the study showed that today’s direct injection engines emit as much as 1,000 times more harmful particles than port fuel injection engines, which is a quite surprising finding. Furthermore, researchers found that GDI engines emit up to 10 times more particles than modern diesel engines.

Researchers said that these types of engines work with higher pressure in their cylinders, which is why they tend to generate greater amounts of particles, which increase air pollution. This is despite the fact that GDI engines produce less CO2, because they can control the amount of fuel that is injected more accurately.

Three different vehicles powered by GDI engines were included in the study. It’s the Ford Focus, with the incredibly efficient and innovative 1.0-liter EcoBoost engine, the Renault Megane, with a 1.2-liter Energy TCe engine under its hood, as well as the Hyundai i40 with a 1.6-liter engine. One very significant revelation that the study provided is that the emission levels of these cars could be substantially lowered if a filter is installed, which only costs about $80.

Greg Archer, program manager with the European Federation for Transport and Environment, said: “Vehicle tests show that without the use of gasoline particulate filters (GPF), more particles are emitted from gasoline direct injection (GDI) engines than diesels”. He added that this is why vehicles powered by GDI engines may exceed future European emission limits (the Euro 6 standard). Even though filters are not expensive at all, car makers have no intention of installing them in their vehicles.

In 2017, the European Union will enact new, stricter emission standards, which all car makers will have to comply with. Current GDI engines exceed emissions limits that are supposed to go into effect in about three years. That’s why European Federation for Transport and Environment suggests that all production vehicles powered by GDI engines come with exhaust filters as part of the standard equipment, which would help reduce air pollution, and prevent hundreds of thousands of deaths that are caused by it each year.


Jordan Perch is an automotive fanatic and “green cars” specialist. He is a writer for DMV.com, a collaborative community for US drivers.

  • Jordan Perch

    Jordan Perch is an automotive blogger writing for DMV.com, a website that aims to help drivers handle all DMV­ related tasks without the stress and hassle that they usually involve. A devoted car enthusiast, he likes to write about the latest in the auto industry, focusing on vehicle safety technologies, green vehicles and driverless cars. Car reviews, car prices and auto shows are also among the things being discussed in his blog posts. Drivers looking to save on auto insurance, or car buyers trying to determine what car fits their needs the most, might find his blog posts pretty helpful.

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