Straight weight oil??
 

When I bought my Nova a few weeks back....I asked him what oil and weight he was running. He said he starts out with VR1 20w-50 and moves to straight 40w in the hot of the summer.

Is heat the main reason why you see some running straight weight vs. the multi viscosity oils?....or are there other advantages??

Thanks!

You run thick straight oil in the summer when the engine has loose tolerances