Direct Injection Cars Lockhart TX
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The Wonder of Direct Injection
The Wonder of Direct Injection By Zach Bowman, DriverSide Contributing Editor
A typical direct-injection
engine cylinder.
Car companies like to bombard customers with slick-sounding jargon during advertisements. It seems like each new model brings some new form of life-altering technology that’s going to save the world one horsepower or one drop of fuel at a time. The thing is, nine times out of 10, the technical-sounding phrases you’re hearing are just ad-fueled nonsense. We say 90 percent of the time because occasionally manufacturers come up with a new bit of tech that can change our threshold for what we consider efficient. Or powerful, for that matter. That’s the case with the rash of direct-injection engines that have surfaced over the past few months.
Mercedes-Benz utilized
direct-injection in the
1954 300SL. 
Porsche's new line of
direct-injection engines
are the company's most
fuel efficient and
powerful.
Direct-injection engines are nothing new. In fact, they’ve been around since World War II when the technology was first implemented in the German Messerschmitt fighter plane. The fuel-injection system helped to give the planes a slight horsepower and range advantage over the Allied craft of the time. Eventually, stagnant development caught up the Axis, allowing British and American designs to overtake the Messerschmitt.
But we’re not here to talk about fighter planes. Since those terrors of London were powered by Mercedes-Benz engines, it’s no surprise the first road-going variant popped up in a Silver Arrow. What really raises some eyebrows is exactly which Mercedes received the special fuel system. Hands down one of the most easily-recognizable and gorgeous cars ever created, the 1954 Mercedes-Benz 300SL Gullwing Coupe, was the very first car to boast a direct-injection engine. From these elegant beginnings, the tech spread to the likes of Volkswagen, Mazda and Mitsubishi. Today, just about every major manufacturer has at least one direct-injection engine on the option sheet.
To really grasp what makes a DI engine so much different from the fuel-injected Accord sitting in your driveway, let’s take a look at a standard fuel-injected engine. After leaving your gas tank, fuel travels through the fuel lines until it reaches your vehicle’s fuel rail (if you have a V-6 or V-8, there may be two fuel rails). At this point, the fuel injectors measure out a specific amount of fuel based on engine load, throttle position, atmospheric pressure and temperature and inject it at a relatively low pressure into the intake manifold directly before your engine’s intake valves. Here, the fuel mixes with the air in the intake manifold and gets sucked into the combustion chamber. The whole process is controlled by your vehicle’s computer.
The result is a controlled system that saves vast amounts of fuel and generates more horsepower compared to carburetion, the other fo...