Non aviation oil question

[Tarheelpilot]

I just bought a car. It’s a turbo 3.0L V6 and specs 0w-20.

So the owners group has lots of guys running 5 weight oil rather than the 0. There appears to be reputable evidence the zero weight is not doing the best job hence many owners using the 5 weight. Although Im not convinced especially with the turbo lubrication running the heavier oil.

I know there’s a handful of you smart engineers running around here with extensive engine experience. Is this ******** or any chance it may be legitimate.

My typical stance is follow the manufacturer recommendations but I do know some guys with the NA version of this engine that did follow the recommendations and they had the opportunity to rebuild their engines with spun mains and significant wear very early in the life span.

Any opinions?

 

[KE5BM]

One of my junior folks is currently fighting with his car's manufacturer over engine warranty due to oil weight. His engine blew a hole through one of the pistons. This is a known issue for this particular model. However, the hang up is centering on the weight of oil that was used. Point being...if the owner's manual says to use 90 weight gear oil for motor oil, that'd better be what you use if you ever need to make a claim.

Further, most people who want to split hairs over 0 "weight" versus 5 "weight" or anything else clearly don't know jack s**** about oil. That little "w" in the viscosity doesn't mean "weight." It means "winter."

 

[Tarheelpilot]

One of my junior folks is currently fighting with his car's manufacturer over engine warranty due to oil weight. His engine blew a hole through one of the pistons. This is a known issue for this particular model. However, the hang up is centering on the weight of oil that was used. Point being...if the owner's manual says to use 90 weight gear oil for motor oil, that'd better be what you use if you ever need to make a claim.

Further, most people who want to split hairs over 0 "weight" versus 5 "weight" or anything else clearly don't know jack s**** about oil. That little "w" in the viscosity doesn't mean "weight." It means "winter."

Specifically the number to the left of the w is the viscosity at winter temps. So while I do know more than “Jack ****” about oil I was looking for more in depth technical knowledge.

 

[KE5BM]

If the manual states to use 0w, use 0w. I'm willing to bet the folks who have had the opportunity to rebuild their engines were probably not using their engines in the way the manufacturer intended. Similar to those who like to race their Honda Civics that they've tuned up but neglected the transmission. If your needs fall within the average driver, follow the manufacturer guidelines. If you're taking your car to the local track once or twice a month, you'll definitely need to consider using a heavier oil for all the reasons you mentioned...namely the turbo. Just understand that once the smoke escapes, you'll be rebuilding your own stuff with no help from the OEM.

There's been a lot of discussion in recent years about the thinner viscosities. Allegedly the 0w-20 flavor is good for gas mileage. I've never really noticed an appreciable difference. What I HAVE noticed, however is that today's 0w-20s and 0w-30s perform at least as well as dad and granddaddy's 10w-30. Sadly, most of the "evidence" out there on the interwebs is largely subjective and hardly scientific. Most oil companies keep their testing locked tight due to competition. The best way to analyze your own needs is to utilize one of the several oil analysis companies out there. I prefer Blackstone. Run one oil change interval on the OEM recommended viscosity and then do the next one in your chosen flavor. See what, if anything changes. Gas mileage will likely be the first to suffer, but an oil analysis will indicate any abnormal wear.

 

[455 Bravo Uniform]

There’s really no way to know predictively. Only after comparison of so many guys and miles running the 5 vs 0 would there be enough actionable info. And then it would still be anecdotal and under uncontrolled conditions.

 

[mondtster]

The “0” or “5” in the XwXX oil specification isn’t a primary concern. It is the latter part of the oil spec that is.

In the US, the auto manufacturers are specing oil that help meet fuel economy requirements. That doesn’t necessarily coincide with what offers the best lubrication. You may need to jump from say a 20 weight oil to a 30 or 40 weight oil to achieve the desired protection.

Here is a recent incident and how an OEM addressed it.