Originally Posted by tblt44
Mobil 1 5w 30 and penzoil ultra platinum still look like the oil when it went into freezer.
Valvoline maxlife red bottle, supertech 10w 30 looked waxy.
0w 40 castrol somewhere inbetween
1) there's nothing credible to learn from this "test"
2) towing 4500 lbs at 3k rpm isn't hard on an engine at all. The load is well within the towing limits of the vehicle, and very high rpm (high reciprocating stresses) or very low rpm (low film boundary and lugging engine) are issues but not 3k rpm.