That would depend on which of the various flavors of either you traded between. If they are equivalent DEXOS1Gen2/3/ILSAC GF6/ACEA C2 then they would be about the same.
If that trade from one of the above was for a DEXOS2/ACEA C3/C4 you would have traded up. These have higher minimum HTHS viscosity values than the SAE *W30 values. More wear protection. Kind of important for a 3500 towing, right? Just say'n.
Doesn't this statement say, and yes, I'm asking, not telling, that the only important parameter is milage in determining the useful life of oil? Or at minimum, that without exception, 3,750 miles will always shows "barely used".
In addition, Blackstone does not test for 1.) Oxidation 2.) Nitration. It does not routinely include 3.) TAN. Which you kind of need to condemn on TBN. They use some rather crude tests for water, fuel & glycol. And quite concerning I see among the hundreds of test I looked at a surprising array of viscosity measurements outside SAE standards considered Okay. Oh and they mix test types for viscosity outside standards. SUS at 40C ??, Instead of cSt. ?
Now, all that said...What parameters is oil condemned on? And what agreement is there between labs on the exact levels for same. What basis in SCIENCE is there for those values? i.e. One lab condemns on a TBN of 1, another at 3, another at 50% or even 60% of the baseline. (which is often assumed instead of measured) Another at the TAN/TBN crossing point? Which method does the FACTS and SCIENCE support?
Hint, Regulation and Social Peer Pressure are currently overriding Facts and Truth.
Most labs don't measure Oxidation. Those that do, some condemn on 10 abs units over baseline. Some on 20-25 or even 30 units absent baseline. Oxidation is kind of important.
How many routinely measure cleanliness?
Just raising questions and offering observations.