Unless it is synthetic. Synthetic 20w50 flows better than regular 10w30 when cold.
Originally Posted by vtbob
Just a caution on moving to 15/50 oil. It is more vicious and will quiet some of the looser valve lash.
But being more vicious, it pumps harder, flows more slowly.
Much of engine wear is on start up, before the oil gets in place to "float" the bearing, etc.
The 15/50 will be slower in getting the lubrication around the engine at start up