Wow the expert in a laboratory setting says "5/20 vs thick showed dramatic increase in wear". Wow who wants to call this lab guy a liar.
Pretty much.
But now you do need that 210 thermostat to overcome any power loss due to cool oil.
A well known at the time NASCAR engine builder explained it to me when I questioned why they wanted a lower temp range oil temperature gauge. The were running much tighter clearances with much thinner oil and making a few more horsepower as a result of the lessening in parasitic drag. He explained, "Its like getting a crowd through a door. The thicker crowd will make it through the wider door no sweat. You try to take that some crowd through a smaller doorway and somebody is going to feel the pain plus fewer can make it through. It's the same as lubricant molecules. Tighter clearances (like with modern engine bearings and especially VVT phazer orifices) require thinner oil."
Just so you know the same exact block and heads on your 3.5 were used on the gt. As far as tolerance go. And that runs off 5w50. In fact a lot of engine builder on the 3.5 have ran 5w50. Including myself. My last 15 3.5 was over 500whp and made it to 418k withou. using a drop on oil at 5 percent oil life left.
I understand that but the point was the tolerances are not different. So it won’t hurt anything.
