GM vortec 5.3L- ‘07-‘13 (5w-30) vs ‘14-‘18 (0w-20)

[CheezWhiz]

I assume you've seen Hot Rod mag where they grab a junkyard LS with a zillion miles, put two turbos on it, run on a dyno and just keep cranking boost until they hit 1200 hp and it doesn't fail? These rigs are pretty stout. I wouldn't be too worried about 20 vs 30wt. I ran 20 weight in my 327 Chevy II back it the 60s and it was fine.

probably a pre-afm LS engine, iron block.

 

[Ram02]

Just Stick to what’s on the oil cap . Don’t ever try to out think the engineers that design the engine. Just like lifetime tranny fluids . It’s designed to never be serviced NEVER . Trust

 

[barkingspider]

Yeah I would stick w xW30 on the older 5.3s

 

[Rat407]

Will not hurt anything to run 0w-20. At least it didn't hurt my 2002 Silverado with the 5.3 and at 150k miles already on it. I used 0w-20 and 5w-20 with no issues for 10k miles. The UOA's didn't show any major differences over running 5w-30. This is also with towing a 4Klbs trailer.

 

[wolfox03SS]

I also vote for an "I wouldn't". Not in the older/ classic GM SBC's, TBI's or Vortec series engines. Especially dependant on application:

I certainly would not ever do it on a truck or a performance spec enginebody application.