Anyone run 5 30 synthetic or 5 40 synthetic

I run rotella 5w40 synthetic in my apu and rotella 15w40 in my truck engine ..I dont run extended drains on either .
I change truck oil at 15 to 20k and service the apu at the same time .

 

T6 5W-40 for me....

 

My dd16 has 10w30 in it, I’ve been thinking about going to something a little heavier, due to the fact that my idle oil pressure seems low at 14psi hot

 

If that's below the minimum spec for hot idle, heavier oil is nothing more than a band-aid. If its within spec, who cares. Some engines are low pressure and high flow.

 

You might be due for o-rings on the oil pick-up tubes. It's a known issue with DD13/DD15/DD16.

 

Not to mention making a complete mess around every grease fitting.

 

10 psi is the minimum idle oil pressure.

 

When you get a full service done at a service facility, dealers included, do you know how they get air out of the system? They run it on ether till it clears, with the hammer down.

In the cassette they use for training to do services it tells them to use full throttle to start the truck while cranking but fail to say let up when it starts so WFO on a dry start,
Just an FYI to consider.
Not all dealers are the same.

 

I have been running T6 5w40 in my D13 but Blackstone says my viscosity is a little low. I'm thinking of switching back to T4 15w-40.

 

At operating temperature both oils will have the same viscosity [40].

Syn. has a higher shear strength than con.

Are you trying to band-aid a mechanical problem?