If you change out your oil that much, you should invest in a oil filtering system, even if you only do minimal passes. If your engine never over-heats, and doesn't get massive amount of dirt in anywhere, you can keep reusing your oil. One thing about the synthetic vs blends, I had seen a noticable acceleration improvement on my sister's oval track SBC from the synthetic-blend to full-snythetic transition.
I would stick with full-synthetics simply because it relieves friction more than the regular blends. If you have had only good things with the synthetic-blend and weren't satisfied with the full-synthetic performance, stick with the blend!
Have you tried lower viscosity oil at the track to see any differences?
Jim "iron Giant" Fahlin ~ A high performance car is like a guitar, you have to tune it to achieve your best operation and pull ahead of the competition.
Last edited by 385serieshemi; 06-19-2010 at 09:17 PM.