TDi, Turbocharged Direct Injection engines have it all; they are fun to drive, they are more powerful; they are extremely economical as well as very efficient. With all these attributes why would anyone even think twice before buying one?
How does a Volkswagen TDi diesel engine work?
For fuel to burn it requires air, huge volumes of it. Some vehicle manufacturers make the engine bigger which defeats the purpose of efficiency and weight while others solve the problem by adding a turbocharger which is driven by exhaust gasses which are free. The objective is to get more air into the cylinder.
Once air is pulled through the turbocharger it then runs through an intercooler which drops the temperature. This is important because cool air does not take up as much space as hot air. The air enters the engine combustion chamber, diesel fuel is injected at very high pressure and combustion takes place. It is the combination of atomized fuel and cool air that makes for cleaner and more efficient combustion.
Because a Volkswagen TDi diesel engine burns fuel more efficiently they produce greater power, even when the engine is running a low RPMs. This engine offers superior performance and higher torque for superior pulling power than any traditional fuel injected engine. High efficiency results in lower emissions and higher mileage; it is definitely a win-win for both the owner and the environment.
To increase the power and torque Volkswagen use variable turbine technology on their TDi engines. This approach allows the engine to pull in more air which is needed for combustion while the engine rev’s stay the same. A turbocharger uses the energy of spent exhaust gas. A turbine which is in the exhaust gas stream turns another turbine in the intake air stream, this compresses the intake air. This air is then cooled; the result is enhanced power and efficiency.
One problem with a turbocharger is “lag.” A turbocharger needs high gas pressure to work properly, this is available only when the engine is running at high revs. To avoid this lag Volkswagen uses a variable turbine geometry turbocharger. As the engine revs fall an on-board control system adjusts a series of vanes, reducing the cross section which in turn increases the speed of the exhaust flow and the gas pressure. As the engine RPMs increase just the opposite happens, the inlet cross section increases.
Combined with high pressure fuel injection which atomizes the fuel, the result is better fuel burning, increased efficiency and reduced emissions.
The Volkswagen Tdi diesel engine is available in the new VW Passat. To see for yourself how far diesel technology has advanced, visit Business name site.