Been thinking about different oils lately since i was dealing with my skid steer and all...

 

What about running an 0w40 oil in these trucks? I've always wondered what 15w40 was doing to my truck in dead winter startups and it not being plugged in...

First year I bought my truck I used 0-40 full synthetic Mobil 1,  then I done some research and realized I don't live in cold enough climate to need to do so, so I've been using 15 40 ever since. Will it hurt the engine using 0 40 probably not any more than starting it with 15 40 on the cold engine.

Hex,

 

Here are the viscosity curves for a 15-40w and a 5-40w oil.    The red line is what you are interested in.  they are mainly different below the 30c (86 F) temperature, and really different below 15C (60F).  They mimic each other above that.   During winter, if you do a lot of cold starts, you could use the 0 weight and not worry about it when it gets back to normal starting temperatures. 

Out here you will be changing oil nearly weekly for those weather conditions. Like this morning it dipped down to +20*F and next couple of mornings be cold then it will pop right back up again. Cold mornings out here do happen be never last for a long period of time.

 

Still, I look at all the logging trucks sitting out in the dirt lot being fired up in the morning no block heater and standard old 15w-40.