Scott,
I'm not sure why 'thick'. Maybe there was a sloshing consideration. As the shop flunky I serviced the air cleaners. The oil reservoir had a level mark stamped into the pan and I was told never to overfill them. I assumed if it were overfilled the excess oil would choke off the incoming air, this led me to believe that light weight oil sloshing around in the tub might cause problems too. I could have been sniffing too much solvent.
Stuart
