Running heavier oil than spec

[fantastic]

View attachment 345347

Certainly get some 40 or 50 grade in there. 15w-50 Mobil if you're normally above 20F. 15w-40 HDEO next. What are you thinking?

 

[Auto tech]

About 200k. Synthetic. My fingers are crossed. Do you have any predictions?

Hard to say without looking at it

 

[Auto tech]

About 200k. Synthetic. 5w30. Do you have any predictions for the longevity? It's a clean truck and has a decent maintenance record. It did have several different owners, but the last guy took very good care of it according to the shop he went to.

Hard to predict. I've seen engines in horrible condition continuing to run. They may consume oil or have lots of blow-by or smoky exhaust but still running. Those 4.3 engines were awesome. I have a 1994 4.3. they did tend to shed lots of iron that had you not had the magnet drain plug you may not have realized

 

[4wd]

Had a 2005 - ran Mobil 1 5W-30 or Delvac 15W-40
Many of them live long lives on the road and water …

 

[PBlackard]

Not many vehicles use magnetic drain plugs for oil (transmission, yeah). Something tells me this has been ongoing and the previous owner installed that to monitor.

My 2000 Chevy Express with the 4.3 Vortec came with the magnetic plug for the engine oil drain.