Need thicker oil?
 

I've noticed lately while towing (in AZ it's hot) that the oil pressure gets low. For example after towing for 30mins up a hill the oil pressure maybe get's up to 25. Then when I come to a stop it drops way down to 10.

Back in the day when we towed w/ a diesel excursion (no I don't miss it) we'd put thicker oil in during the summer. Has anyone deviated from the 5w-20 and put something thicker in? Would it help w/ my low oil pressure? The water temperature stays in check around 210-235. It's this low oil pressure I'm focus in on.

In the summer i do add lucas oil additive when i change the oil. Then in the fall I change the oil again and just run straight 5w30. I dont tow anything heavy though. Just a 16' boat and snowmobiles. Before synthetic oils this was something i did for added protection against wear and i have just continued doing with the synthetics.

Your oil pressure seems low to start with. My 03 typically sits around 40-45 regardless of what im doing with the truck.

I noticed your sig after i posted and you have an 08. So maybe someone with an 08-09. Can chime in on what their oil pressure sits at. Still seems low to me.

I have an 08 and I’ve seen plenty of others and the oil pressure fluctuates between 25-45. I also have an 05 and that sits at 40 almost all the time

5w30 is what you should be running.

Yep, says it right on the fill cap. Just wondering if anyone has had ventured out and tried something different. Maybe I should go check out the silverado forums where they do more towing.

As these engines get older I've started running thicker 10w40. On my GMC pickup (5.3L but essentially the exact same GM LS engine) it really helps - it had gotten to where it was using 2 quarts a month. Once I switched it over to 10w40 it uses almost none and has been perfectly fine for a few years. Also started running the same (Amsoil) 10w40 in my H2. We do have a pretty warm climate here so I'm not terribly worried about extreme cold weather.

Thank you, that was the type of info I was looking for. I'm going to change the oil here shortly and I'l try the Amsoil 10w40. I'm also going to try that Amsoil coolant boost.

Theirs or any other brand of the coolant boosters should also help with temps some. Its not dramatic but it helps.

Let me know your results with 10-40 . My h2 was at 40 steady. Little by little is going down . Now at 25 idle . 40 2000rpm
Also got a messenger for low pressure oil right at start.
I've been wanting to do a test with a analog gauge but disconnect the oil sensor is a big PIA

Just got back from a 2700 mile towing trip w/ amsoil 10w-40 and filter. The pressure did increase a little. Just enough for me not to worry about it much. It would hold at 30 and stay slightly above 10 when stopped. I don't know if this had anything to do w/ it being amsoil or the weight of the oil. So the next oil change I'll go back to mobile 1 but use 10w-40.