I think synthetics are best for SVT for 3 reasons..
1) Be it from oil starvation or crank whip, Duratecs have an issue with spun bearings. Key oil factor relating to bearing protection is viscosity index (better VI = mre durable oil film on bearing). Synthetics are better in measure VI (Amsoil best, Mobil 1 & Redline next best IIRC).
2) SVT Duratec is about the highest reving Domestic street engine (actually tied with SVT Cobra 4.6 at 7K RPM & SVT Focus at 7.2K). SVT has peak power at 6600+ RPM which means you are near redline alot.
3) Synthetic is factory fill on some of the best engines...Vette, MB, BMW, Porsche...makes you wonder??
A "typical" motor that runs under 5K RPM most of the time with no spun bearing issues......I may not bother with synthetic. But an SVT motor......
