Since it is getting warmer in Southern Californa, I decided to change my oil with some synthetic 5W-40 oil. My engine seems to run so quiet and smooth on this oil. It is still a little early to fully tell, but the engine seems to not ping when I am running straight 91 octane gas when going up steep hills.

CALLISTO, what has been your experience with 5W-40 oil in 2.5 NA?

Anyone else have experience?

 

If you do a db. testing, you would find that most any oil multi-velocity for the first few hundred miles the engine will be slightly quieter. But as you acquire more miles the engine "WILL" return to it normal sounds.
Pinging will start before the human ear can hear it. The only way to tell if your pining is to watch your timing and temperature values reported by the ecu.

But for what it is worth my temperatures here not much different than your exceed 106F with a radiated tarmac over 180F at times I run 10w-40 or 5w-40. Whichever I grab first from my stock. LOL

I would highly recommend because of the DIY that you are to install a manual fan switch so you can run your cooling fans more often than when your coolant reaches or exceeds 225F (often when stop and go summer temperatures and in traffic running your AC) ) or the AC use.

 

Do you have a write-up somewhere on how you installed a manual switch to turn on the fan? Did you have to apply 12 volts to something, or did you have to ground something to turn on the fan?

 

Seems like 0W-20 isn't what we should use then?

 

There are 2 ways to choose motor oil. The easy way simply use what is recommended on the oil cap (lol) owner's manual or service guide or choose by your operating environment and type of driving. (better way)

 

I think so but you would need to find it? There are to many pages now on my thread.

 

After running 0w20 in our 2013 sport, I used up a jug of 0w40 (pennzoil/quaker state) for the summer oil change. The engine was so quiet you can actually hear the syncros spooling in the transmission during downshifts along with input shaft sounds. I actually thought I had a bad pilot bearing in the transmission with the attenuation of the engine noise, but it's just normal mechanical sounds you don't hear with thinner oil. About 1000miles on the 0w40 so far and it's still so quiet.

 

LOL first oil is described correctly by viscosity not thinner or thicker. And as i said if one uses a simple db meter you may find that the mind is strong influence on the numbers of the oil used rather real facts on how motor oil works and a strong preconception of what people feel things should be.

 

Be that as it may, any Xw40 is thicker than any Xw20 weight oil at operating temperature.



The ability of a 40 weight oil to maintain MOFT at higher temperatures than a 20 weight along with KV100 and HTHSV150 is well understood. While there is a possibility of achieving equal HTHS ratings between a 20 and 40 weight oil (if the 20 weight isn't using viscosity improvers), it rarely happens. The mazda 2.0 skyactive is a surprisingly noisy modern engine. To my ear, this change of sound occurred right after the oil change while the vehicle was still on the ramps.

A great read if you want to delve into the technical aspect of oil rheology:

https://bobistheoilguy.com/forums/th...icated.309930/

 

Climate temperature range is the main reason for the viscosity choice for the average person's vehicle.
Obviously, a vehicle in Brazil will not use the same viscosity as one in Antartica or a track vehicle will not use the same as a daily driver.
One can argue the "benefit or not" of changing viscosities during seasonal temperature fluctuations if not recommended by the manufacturer.
Changing viscosity to quiet an engine is not a physics-based reason it is a personal reason.
The owner's maintenance manual is what the manufacturer recommends.
It's really that simple.