3 Trail Boss Owners: 0W-20 or 5W-30?

[WrenchingMafia]

I’m at 76k miles on my 5.3 Trail Boss and wanted to see what oil grades everyone is running these days. Still using 0W-20 or have some of you switched to 5W-30? Curious what everyone’s preference is and if you noticed any difference in engine noise, oil consumption, fuel mileage, or overall performance.

 

[hawk99gt]

I am running the 5W-30 Full Synthetic Mobile1 at 26k miles. Truck is almost 3 years old. Been running it that for about 2 years. Probably around 12 - 14K miles I started. Everything seems to be running fine so far.

 

[PMW_fab]

0W-20 since brand new, 2022 LT refresh 5.3 just rolled 97K miles and no issues

 

[BigBlackie_'25TB]

I’m at 76k miles on my 5.3 Trail Boss and wanted to see what oil grades everyone is running these days. Still using 0W-20 or have some of you switched to 5W-30? Curious what everyone’s preference is and if you noticed any difference in engine noise, oil consumption, fuel mileage, or overall performance.

Been running 5w30 since I bought the truck with 3297 miles. As you will see the very first UOA is with 0w20. I recently switched to 0w40. I want to see how this weight fairs out where I reside (northern Vermont). I do a UOA every oil change. I will provide all the UOA reports I currently had completed. Once I change my oil again, I will update it for you to compare because it will show UOA with 0w40. Keep in mind the first few oil changes still had the engine "breaking in" so the high numbers for wear are normal. The dates for UOA are listed so you will know when and oil type. I have done a ton of modifications so the fuel mileage sucks...I get on average around 14.0 mpg. Anyhow, here are my UOA reports from 0w20 to 5w30. You will notice the oxidation value is fairly high for the last oil change (4/26/26) and this is because I switched to Amsoil Signature Series from Amsoil Synthetic Blend. The Signature Series is an Ester based formula which runs higher oxidation values.

 

[Murph76]

Nothing lighter than 5w30...might switch myself to 0w40 later after more reports come in on whether its worth it or not

 

[mrcolieman]

I started running Oreilly 5w-30 full synthetic Dexos certified when the warranty ran out on my 2019 5.3AFM. 51k miles and no complaints. 8 qts and an AC Delco PF63 filter (from Amazon) is just under $60. I end up with about 3,500 miles between oil changes at 6 month intervals. With big heavy tires, a heavy winch/bumper and a level it's hard to say if the oil had any effect on my fuel economy. It's still 18ish on the highway and 15ish around town... But when we're driving our trucks it's all about the smiles per gallon right!?!