Yeah the goofy reasons just never end.I share a bias for higher viscosity and believe the push to lower viscosity is pushed by fuel economy and not engine protection. However, fwiw, a Honda mechanic who is pretty experienced and knowledgeable once told me going to a higher viscosity in a J35 (from 0w20 to 5w30) was not a terrific idea because the oil could actually “ride over” and help tear up the rings. That is one person’s view and not definitive but he has been a Honda tech for 20+ years and torn down a lot of J35s related to the VCM issues Honda has had.
The car is out of warranty anyway so it is largely your call, but my way of keeping things simple is to follow what is in the manual. The manufacturers are under pressure for fuel economy, no question, but from having worked for clients in that space I can tell you that customer reputation is very important, and they aren’t going to have cars so that the motors blow up at 100k if the service interval and lubricant requirements are met. That ruins what they call the “customer experience” and they know it will hurt their business tremendously if they do not earn repeat customers.
Good luck with it, whatever you choose.
Using 5w-30 instead of 5w-20
- Thread starter kwg2005
- Start date
Yeah the goofy reasons just never end.
"Ride over" and "tear up the rings" are new ones for me. I'd say there's a pretty good reason he's fixing engines and not engineering them.
All those Honda engines in other countries specing a recommended range of viscosity above xW-20 must really be "tearing up rings".
4WD
$50 site donor 2024
As a consumer, I am baffled why OEMs are not required to publish their B10 rating for each engine/transmission? If data was there, I could make an informed decision to run the cheapest 0w20 certified/approved/etc oil in my car and expect it to live x1000 miles/hours with 90% chance of success. In absence of that data, I assume the OEM warranty period is all they need to care about and thus out of that period their recommendation worth as much as their marketing.
Wow. Tough crowd here. I have a lot of respect for people with actual hands on experience - building and rebuilding engines is a real skill. I guess a lot of the folks here must be petroleum engineers. Have a good weekend fellas.
Wont cause any issues.
Sometimes imagination supersedes physics.
He was speaking from experience.
To be clear I don’t think this kind of thing is likely, but once again Honda is one of the best engine manufacturers in the world. Their engine tolerances, aside from perhaps Toyota, are just amazing. Those are the folks who spec the oil viscosity. I don’t see much upside, and perhaps some chance of a downside, from not following what they say. But if you or others here know better, publish your CV and we can judge for ourselves. Otherwise the average person is well served to follow the manual, keep it full, and keep it clean, particularly if the engine has no issues.
Shame, I thought this forum would be more useful.
Enjoy your weekend.
Here is a screenshot from the Russian manual for my 2014 MDX with the J35Y5...a more modern revision that notably is GDI. Translated, the manual says to use 0W-20 or 0W-30, and if those are unavailable use 5W-30. Not at all attacking your friend's experience, but the 0W-20 exclusive spec really is a US/CA thing.
And they specify a range of viscosity above xW-20 for the same engines in other parts of the world. So if thicker oils above xW-20 "tore up rings" like the mechanic theorized, there would be engines wearing out faster in those areas than in the USA. And besides, what about all other brands of engines that run oil thicker than xW-20 ... are they all wearing out rings at a much faster rate. No, they aren't. So the Honda mechanic most likely never studied Tribology or read any studies on engine wear vs oil viscosity, and came up with some "theory" with no real logic behind it that the rings must have gotten "torn up" from using xW-30 instead of xW-20. Maybe the guy was running a K&N air filter in dusty conditions instead.
Ahha yes the “tolerances” thing. I bet the tolerances on engine parts hasn’t changed much at all in a very long time regardless of the manufacturer.
The engines are not “designed for” a specific oil grade and certainly not because of the tolerances.
I’d say the forum is being quite useful here.
Rod and crank bearing clearances are pretty tight (see below) on the Ford Coyote/Voodoo/Roadrunner V8 (all similar configurations), and Ford specs anywhere from 5W-20 to 5W-50 depending on what car those engines are in.
To add, the clearance on rings to cylinder bore is zero (mainly running in the boundary and mixed lubrication realm). And many HTHS viscosity vs wear studies show that ring wear is pretty dependent on HTHS viscosity, and the wear rate decreases as HTHS viscosity increases. Of all components in an engine, the rings live in a pretty harsh and demanding environment, and usually wear out before any other engine component.
MolaKule
Staff member
That person's view is definitely not correct as he seems to be making up terms to describe some imaginary action.
A slightly thicker oil film will most likely seal the combustion gasses better but the rings will actually flex and move.
I think it would benefit you to read more and pass judgement less.
This forum is brimming over with knowledge and fact, from 100s, if not thousands of professionals - see Molakule's comment for instance.
Ask questions, challenge, even correct when appropriate, but also, park your ego.
If you leave (your choice, of course!) you'll only be depriving yourself of a generous resource.
Cheers
I think we need a "Thicker vs Thinner oil" pin in this forum.
I've been posting and lurking on this site for over 20 years and I still need a refresher every now and then.
I've been posting and lurking on this site for over 20 years and I still need a refresher every now and then.
True, we're not at war here. kindness and patience is always preferred over impatience and judgement. My comment could have been worded better.
