The pre-drive indoctrination process at Audi’s glass-and-steel corporatorium attached to Munich’s Franz Josef Strauss Airport didn’t take long to crank into advanced hyperbole. The 2008 Audi TT TDI coupe and roadster were hailed as “the first series production sports cars in the world to use a diesel engine as their power source.” Well, perhaps the big buildup is due to the fact that the TT TDI was launched in parallel with the distinctly more commanding TTS with its turbocharged 265-hp gas-fueled engine, making the TDI appear to be the plain sister of the duo. Of course, where the TTS gets the looks, the TT TDI definitely gets the smarts.
Audi’s 2.0-liter diesel has been comprehensively reengineered this year in preparation for the brave new world of diesel power, and the measures are about such things as quietness and suppressed vibration as well as power and fuel economy. The DOHC 1,968cc inline-4 features common-rail injection with piezo injectors, a measure that improves efficiency and reduces noise. The compression ratio is 16.5:1 (even in this turbocharged engine), but twin balance shafts control vibration. Even the turbo’s vibration is controlled by a special damper.
Source: Inside Line