The European Federation for Transport and Environment (T&E), a European umbrella group that aims to promote environmentally friendlier forms of transportation, would like you to know that there’s a downside to newer, more fuel-efficient gasoline engines: a higher cancer risk linked to vehicle emissions.

The group announced Thursday the results of a study it commissioned from TUV Nord, a German industrial testing and certification agency, concluding that modern gasoline direct-injection (GDI) engines emit 1,000 more fine-particle contaminants than traditional port fuel injection engines. GDI engines use a fuel injector to meter the amount of fuel that enters a cylinder rather than a mixture of fuel and air. The result: more efficient use of gasoline but with greater amounts of fine-particulate emissions.

The study looked at three vehicles with GDI engines: the Ford Motor Company (NYSE:F) Focus compact with its 1.0-liter EcoBoost engine, the Hyundai i40 family car with a 1.6-liter engine and the Renault Megane with its 1.2 liter Energy TCe 115 engine. TUV Nord measured the exhaust levels for these cars and concluded that an $80 filter would make a significant difference at a fairly insignificant price.

“Vehicle tests show that without the use of gasoline particulate filters (GPF), more particles are emitted from gasoline direct injection (GDI) engines than diesels,” Greg Archer, T&E program manager, said in announcing the results of the findings. “On the road, GDI vehicles may therefore exceed future European emissions limits -- the Euro 6 standard. The cost of a filter to eliminate particle emissions is low (around €50), with no fuel economy penalty. Despite this, carmakers are declining to fit filters to GDI cars – thereby worsening urban air pollution.”

On top of that, because modern diesel engines, such as the TDI manufactured by German automaker Volkswagen AG (FRA:VOW), are required to have exhaust filters they actually emit fewer fine particles than regular gas burning engines. Diesel, once the dirty, loud, stinky cousin of internal combustion engines, has come so far that cars burning the fuel are sometimes compared to hybrids in terms of efficiency.

The TUV Nord tests found that particulate emissions in these newer GDI engines (without exhaust filters) exceed the European limits scheduled for 2017. With exhaust filters, the new engines would not only be in compliance, says T&E, but they would also truly be the “great innovation” toward cleaner gas-burning engines that automakers are touring them as.

“It’s time for carmakers to act responsibly and make petrol cars less polluting overall,” said Archer in the report, which can be read in its entirety by clicking here.

For a more technical breakdown of TUV Nord’s testing, click here