Only because synthetic oil is more tolerant of the obscene temperatures generated in the turbo if you install a chip. I have head the turbo glows BRIGHT orange!<p>My dealer recommended to wait until at least 15000 miles before switching to synthetic (as well as waiting the full 5000 miles before the first oil change). In their experience these engines take a LONG time to break in and they have seen at least one engine that was switched to synthetic too soon that was not properly broken in at 26,000 miles. Apparently someone blew a head gasket (not chip related), and when they tore the engine down something about it was not broken in.<p>I don't know how much truth there is to any of the above mileage reccomendations (this has been hotly debated on this forum -- check the archives), but I can say that I switched to synthetic at 15,000 miles (I used Castrol Syntec 10W-30 because it has a slightly higher viscosity rating than Mobil 1 10W-30, and I wanted as thick as I could get without jumping to 5W-50 or 15W-50). At 16,700 miles my car winds up SMOOTHLY and EAGERLY all the way to redline, and still does not use a drop of oil between changes! (knock on wood)<p>Paul<br>'98.5 A4 1.8TQTipS in Pearl

This may not be necessary, but it gave me peace of mind since I drive the car hard. :o)<p>Paul

How much better is the lighting from Xenon's versus European H4s?<br>

Even tho the comparison is to US Stock, the Euro light is certainly closer to US than to Xenon.<p>- Stan<br><ul><li><a href="http://rescomp.stanford.edu/~stanj/Audi/XenonPower.html">Xenon vs. stock</a></li></ul>