I switched to synthetic Maxtron 5w30 from Autogold 5w30 since I knew I was going to run a longer interval this time. Lots of highway miles, but also lots of construction dust and a fair amount of towing in this interval. Used a Wix oil filter. The air filter was Wix also and had about 20 k on it- changed with oil at same time as sample.
I could tell it wasn't shearing down as much as the oil pressure guage would tell me at around 5-6k with the autogold that it was shearing (<20 psi at hot idle). Maxtron kept it 25-30psi hot idle all the way through.
