Originally Posted by TIMZTOY
I don't have the artical.
But a independent company with no affiliation to any Motor oil manufacture, tested every full synthetic oil on the market.
And almost every oil broke Down and stopped "Lubricating" at 2-3,000 miles. Penzoil was the worst at like 1500.
Valvoline was like 8000, Castrol about 5000. Mobil 1 full syn 25,000 miles before it STARTED to brake down.
I run it 10,000 and its still clean'ish when it comes out.
There "clean 5000" is better than most full syn oils
Dang, I dunno, perhaps my engines were not taken care of by PO's, but at 5k, my Mobil1 comes out blacker than coal.