Due for my first oil change at 5k miles. Lots of these miles have been towing. I would like to switch to syn oil but have a couple of ?

Some folks claim to wait a little while to break in before switching to syn…if so, how many miles? I always switch my gassers at first oil change.Is it a good idea to switch at 5k miles?
Which Mobil1 should I use? I was at Wallyworld and could not find one that said it was for diesel engines?

If you like Mobil1, use the Truck and Diesel formula. Make sure it has the required CI+ or whatever your truck requires. You could change now or wait for about 2 more oil changes. If you are towing heavy / boxy items, you should be fine. I run Rotella 5w40 for winter in my 2003 Dodge but I have run the Mobil Delvac 1. It should be the same as the smaller bottles. I started running the Rotella syn. at my first oil change as I wanted the 5w40 rating for winter and I go to norther Wi. and sometimes see extreme cold up there.

I think I would get that oil and filter changed ASAP!! Do a short OCI and then switch to synthetic. My vote would be AmsOil.

i'm running royal purple 15-40. i switched over after about 25k miles because i was getting free changes. i'm hoping that i can get away with only changing it once every 9months. honestly i did not notice any increase in power or mpg.