Does heavier oil = quieter, smoother engine?

[HerrStig]

Originally Posted By: Smokescreen
Non-spec.

Upon a search of your particular engine the "worldwide" oil weight applications, many may be surprised at what they find as to what they see here in North America vs elsewhere.

For example, in the North American owners manual for the 10th gen Toyota Corolla 1.8L (which is a world spec engine), there is only 5w20 and 0w20 oils strongly recommended. If one were to look outside this continent you would see this:

"Toyota genuine oil or equivalent
Oil grade - 20w-50 and 15w 40
API grade SL or SM multigrade
10w-30, 5w30, 5w-20 and 0w-20
API grade SL "energy conserving"
SM "energy conserving"
ILSAC multigrade engine oil

As this is for the same world wide engine for this vehicle, the argument for not moving to a different weight (should you choose) is not an issue and certainly not cause an untimely demise to the engine.

I am not advocating the use of heavier weights, just that you research your engine and know more about its design.
This little contradiction is well known and it's good you brought it up. Soon we'll be regaled with the "benefits" of 0W - 0.

 

[HTSS_TR]

Originally Posted By: 19jacobob93
Absolutely agree with everyone saying thicker oil actually makes lifter tick worse, the opposite of what most people think! With 10w40 my lifters clatter like crazy it's embarrassing haha but with 10w30 they are almost silent

Same with the engine in my 2000 MB E430.

Back in around 2007-2008 the engine was very noisy like a diesel engine, since I bought the car 7-8 years before it had only Mobil 1 0W40. The engine was very quiet for 5-6 years.

I had 10 quarts Pennzoil Platinum 5W20, I tried it instead of recommended Mobil 1 0W40, to my surprise the engine was extremely quiet and throttle response was much better with 5W20. The oil consumption was the same with 0W40 which was/is near zero. I am not saying all MB E430 engines from 1998 till 2003 like thinner oil, but mine does.

Some engines are quieter with thicker oil, some other engines are opposite quieter with thinner oil. You need to try one and then another to see if your particular engine(s) likes thinner or thicker oil.

 

[Pontual]

Lifter tick is louder with heavier oil? Just because they're too dirty and carboned up. Thinner oil flow better in tight spots in dirty lifters. If the lifter is clean, then a heavier oil wouldn't make it louder.

 

[buster]

Depends. Some of the lifters need oil fast and a lighter grade oil can get there faster and reduce noise. In a worn engine, a thicker oil may reduce sound.

 

[A_Harman]

Originally Posted By: Pontual
Lifter tick is louder with heavier oil? Just because they're too dirty and carboned up. Thinner oil flow better in tight spots in dirty lifters. If the lifter is clean, then a heavier oil wouldn't make it louder.


Higher viscosity oils make the plungers in the lifters move more slowly, leading to noise due to slow lash takeup in the valvetrain.

 

[A_Harman]

Originally Posted By: HerrStig
Originally Posted By: 19jacobob93
Absolutely agree with everyone saying thicker oil actually makes lifter tick worse, the opposite of what most people think! With 10w40 my lifters clatter like crazy it's embarrassing haha but with 10w30 they are almost silent
And does it help with solid lifter engines?


The only thing that helps with solid lifter engines is to adjust the lash hot to the minimum allowable clearance.

 

[fdcg27]

I'm not sure about running a fifty grade in an application for which a twenty is recommended.
I can tell you that in my personal experience, going up one grade always brings smoother and quieter operation.
I'll note that all but one of the engines I've tried this with had solid lifters and the lone hydraulic lifter Vulcan had no lifter problems to begin with and none of these engines had anything ugly, like piston slap.
As always, YMMV, but you'll never know unless you try.
I doubt the relevance of your water vs motor oil thought experiment, though.

 

[Oregoonian]

Originally Posted By: Hokiefyd
It does in my experience. Note I'm using xW-30 oil in my 5W-20 spec'd Honda...
IMO....The difference in your situation is most likely undetectable....a figment of your imagination.

 

[fdcg27]

On the contrary, the difference in going up one grade is unmistakable.
Try it and see for yourself.

 

[Pontual]

Originally Posted By: A_Harman
Originally Posted By: Pontual
Lifter tick is louder with heavier oil? Just because they're too dirty and carboned up. Thinner oil flow better in tight spots in dirty lifters. If the lifter is clean, then a heavier oil wouldn't make it louder.


Higher viscosity oils make the plungers in the lifters move more slowly, leading to noise due to slow lash takeup in the valvetrain.


How come? What makes the plunges to move isn't flow but force transfer by pressure in hermetic closed container (check valve ball). And viscosity don't make a decrease on pressure system, just on volume or flow systems. The lash needs a very tiny volume of oil, but lots of pressure damper. As said, the difference is almost irrelevant to be of measurement.

 

[Merkava_4]

Depends on the engine. Some engines can really benefit from thicker oil.

 

[Clevy]

Wildly platform specific and wear dependent.

For example my chargers hemi runs flawlessly and very quiet using a 0w-40 however using the specified 20 grade really doesn't add much if any valvetrain noise.
I have an 88 fox body with a 5.0 that runs less noisy using a 20 grade vs a 30 or 40 but my 6.0 and 5.3 in my Chevys are less noisy with a 40 grade vs the specified 30 grade.
So there isn't any consistent answer. At best it depends......