That's the sort of thing that needs researched, but I don't see it happening so we just keep saying things like "I switched to 5w30 and everything's fine" and vice versa, which is worthless anectodal information that tells us zero. The smarter guys seem to agree that more HTHS decreases wear so I've got that at the top of my "I can't prove it but it makes sense and those dudes all said it" list.Wonder if everything else being equal, if they had used 5W-30 since new (instead of 20 weight oils), if they would be going strong for another 100,000 miles to 300,000 total.
No bickering here at all. A UOA is not the tool to determine comparative wear between oils.Bill7, PLEASE do this test and let us know the results!
It would answer the question and help quash the bickering about this topic.
Anything other than a UOA is guessing, but my guess is that the -30 may have slightly lower wear. Since you are using the same oil/filter combo always, that removes a variable.
Looking forward to the results!
What OCI was used in those miles? What were the operating conditions? What oil and air filters were used? What is the specific engine design?I'm very close to making the decision to switch permanently from 5W-20 to 5W-30.
Please take the next statement with a grain of salt. It's not based on any scientific data, just a feeling.
So many cars end up consuming a ton of oil and can't pass emissions tests and reach end of life at 200k miles.
At that point, people don't want to keep them if they have to add a quart of oil every 500 miles.
Wonder if everything else being equal, if they had used 5W-30 since new (instead of 20 weight oils), if they would be going strong for another 100,000 miles to 300,000 total.
No oil of a higher HT/HS than what is recommended in the manual will damage an engine. Thicker oils help prevent wear, not cause it.