Past, Present and Future of GDI Technology
Take a look at the past, present and future of gasoline direct injection engine technology. The fuel injection design has become more and more popular as a way to boost efficiency, and repair shops are seeing more of these engines in 2020.
In June 2014, National Oil and Lube News featured a story called “Air, Fire and Fuel: The Future of the Combustion Engine.”
Big changes were happening in engine design, and much of it was driven by efficiency targets in the federal government’s Corporate Average Fuel Economy (CAFE) rules.
“CAFE standards are driving the product in the direction that it wouldn’t necessarily have gone on its own,” Jay Kavanaugh, engineering editor at Edmunds.com, told the magazine at the time.
One trend emerged at the time as a combination of features: Smaller engines, direct injection technologies and, often turbocharging.
Automakers have looked at lots of different efficiency tricks in engine technology. Cylinder deactivation, stop-start, hybrid-electric drivetrains and others. None have exploded in popularity like direct-injection for gasoline engines.
Direct injection sprays precise amounts of fuel directly into the combustion chamber which, in communion with a precise spark timing, can maximize the power generated through that process. It’s an alternative to port fuel injection.
In 2015, the U.S. Department of Energy found that GDI (gasoline direct injection) technology exploded onto the scene, reaching nearly 40 percent of market share just seven years into use. That far outpaced competing efficiency-related designs.
In 2019, all automakers offer direct-injection engines for some models. They’re often paired with turbochargers and have smaller displacements than what might have been common before.
“Of all the emerging technologies, gasoline direct injection (GDI) has seen the highest level of adoption among manufacturers, reaching 51% for the 2018 model year,” the DOE wrote in a 2019 report.
Eight of the largest automakers included GDI in more than 75 percent of their vehicles.
There have been some bumps along the way. GDI engines were prone to added deposits on intake valves. The injectors spray at ultra-high pressure, which can blow some gasoline out of the combustion chamber.
Another big issue has been the emergence of low-speed pre-ignition in turbocharged direct injection engines. This “super knock” comes from excessive pressure in the cylinder that leads to abnormal combustion events. LSPI can cause major damage to engines.
The industry has responded to these issues in many ways. Oil companies are altering formulas and additive packages to help combat deposits. Standalone additive companies are developing their own products as well. And engine manufacturers are making design changes to make later models less prone to these issues.