so i was running 20/50 motor oil for many years with Engine leaks the other day i did a oil change for sh@ts and giggles i went with 10/40 motor oil surprisingly my oil leaks have decreased dramatically don't get me wrong I still have oil leaks but not as bad
so my question is why is that ?
i have a 1990 toyota 22re 2wd

 

The 20/50, being thicker, probably allowed sludge to linger and solidify in the cracks where leaks were.

 

my guess is higher oil pressure with the heavier oil

 

Depends just where your leaks are.

The 10/40 will drain back to the oil pan faster it might be just enough for you to see the difference in your leaks.

Has it got to the point people ask you not to come visit and even Walmart complains about your oil puddles