I live in West Ky. It is as cold as it has been in years here. It is about 10-15*F. I have a block heater that I will plug in the night before the truck will be used. For the most part it is not used unless it's racing season (drag racing). I would like to know if it would be ok to run 40w year around. The temps will usualy be 40*-100*F during most of its operation. The truck calls for 15w-40, but I can get the 40w for free. It's Rotella. Thanks!!!

 

The problem with running straight 40W is that it's like molasses at start up while it's cold, and I know what you mean about it being colder than it has been in a long time, we're getting it too. You might consider using a 5W40 right now like Rotella or Mobil1. I wouldn't even rish it. But you might try a pour test with the free oil while it's 10f.

 

IF you plug it in for 4-6 hr min before starting it, and
IF you let it fully warm up before you drive even close to hard..... I see no problem.

Heating the coolant well does heat up the block, and in turn does somewhat preheat the oil.
I proved this to my satisfaction when I had an oil temp gauge!

RJ

 

Or put a oil pan heater on too...for straight 40w

 

So for th esummertime, the oil would be absolutely no problem though right? thanks again guys!