Why Do Knowledgeable Folks on Here use 20 wt Oil

[Shel_B]

For me it's roadsalt ...

... or texting while driving.

 

[bighead2586]

I love all these thick vs thin arguments. Good fun I don't care what anyone says.

 

[K.Aoi]

BITOG never changes.

 

[cookand]

Come on, list 20 of 'em for us ! Love it when you do that !

Me too. I know it’s in jest but when I first joined (and even now) it was quite helpful

 

[wemay]

Oh yeah, that title was gonna invite freindly banter...​

"Why Do Knowledgeable Folks on Here use 20 wt Oil"​

 

[CKN]

We all know more than the engineers that designed our engines….right?

Of course-my 5.3 should have blown up running 0W/20 pulling a 5,000 pound travel trailer up to 10,000 feet elevation on a 90 degree day.....

 

[Mechanician]

Another opportunity to state an opinion - never gets old for many folks.

 

[fdcg27]

We should all know that any engine running the recommended grade changed as recommended will outlast the rest of the vehicle it's installed in.
Why not pocket the fuel cost savings over the life on the vehicle, which do add up over the years and miles?
I used to buy into the thicker is better arguments, but my more recent experience with 0W-20 recommended engines leads me to think otherwise.

 

[Glenda W.]

Why do knowledgeable folks mix oils?

 

[OVERKILL]

Yes I realize that. But read my post. The switch was made around 2000. Wish I could find the SAE pub tghat discussed engine life..

The 5W-20 grade started to show up en-masse in domestic passenger car applications for CAFE in the late 90's, early 2000's with Ford really leading the charge with the Modular, but they back-spec'd a whole list of engines that were validated to be OK on 5W-20 but had never spec'd it.

The Japanese had already been experimenting with this, and thinner, at the time.

5W-20 was not a common grade in the passenger car scene until Ford really took it mainstream, but of course the original Mobil 1 was a 5W-20, and the SAE 20 grade was around for cold climate use, as well as 5W-20, 10W-20, 15W-20 and 20W-20 since before the 2nd World War.

Bearing surface area needs to change3 with lower viscosities. To accomodate load/rpm/viscosity graph. But we are talking in reducing from 10ish to 8ish cSts.

Only once you get down below 2.6cP HTHS. That's why Ford was able to back-spec engines from the 80's to 5W-20, because 5W-20 has an HTHS of 2.6cP. It's when you get down to 0W-16, 0W-12 and 0W-8 where the HTHS is much lower that you have to start increasing bearing surface area.

 

[OVERKILL]

Yes but SAE grade requirements have changed numerous times since then. Today’s 20-grade oils are not the same as they were 50 years ago.

No, but the floor of 2.6cP for HTHS is the threshold where you need to make engine design changes, which I think is an important distinction. The old monograde SAE 20 oils had a higher HTHS, but there were other xW-20 grades available, probably the most common being 20W-20, but there was also 15W-20 and 10W-20 and even 5W-20 (the original M1).

 

[RevvCats]

I kept running my mustang GT with 5w-20 while it was under warranty because I was curious how well the oil would hold up.

Well after 7.4k miles with the factory motorcraft semi-syn, 10.2k miles with Mobil 1, 10.4k miles with Valvoline, 10.2k miles with Mobil 1 again, and 8.7k with Castrol Edge I never saw any signs high wear metals or any signs of oil viscosity breakdown in any of the oil tests I did. The internet told me that was supposed to doubly destroy my engine

I recently finished a 8.2k mile run with Castrol Edge EP 5w-30 and I’m waiting on the analysis results.

Heck next winter I might run Mobil 1 0w-16 for the fun of it since that oil seems to have a very high amount of PAO base stock.

 

[Al]

The 5W-20 grade started to show up en-masse in domestic passenger car applications for CAFE in the late 90's, early 2000's with Ford really leading the charge with the Modular, but they back-spec'd a whole list of engines that were validated to be OK on 5W-20 but had never spec'd it.

The Japanese had already been experimenting with this, and thinner, at the time.

5W-20 was not a common grade in the passenger car scene until Ford really took it mainstream, but of course the original Mobil 1 was a 5W-20, and the SAE 20 grade was around for cold climate use, as well as 5W-20, 10W-20, 15W-20 and 20W-20 since before the 2nd World War.


Only once you get down below 2.6cP HTHS. That's why Ford was able to back-spec engines from the 80's to 5W-20, because 5W-20 has an HTHS of 2.6cP. It's when you get down to 0W-16, 0W-12 and 0W-8 where the HTHS is much lower that you have to start increasing bearing surface area.

Good post. Some of that comes back to me now.

 

[Al]

Why not pocket the fuel cost savings over the life on the vehicle, which do add up over the years and miles?

Good point

 

[Al]

Don't overlook the additive package. Many anti-wear elements are built into the additive packages, some of which help "strengthen" the thinner viscosity oils that are frequently used today.

I guess that the thinner viscosity does not protect better by itself. Thats why I like to use the heavier oil with the higher moly and boron.

 

[walterjay]

What are some examples of a thicker 0-20? OVERKILL noted Mobil-1 EP.

 

[Hall]

The issue comes in when people say that an engine is “designed for” (as in requires) a grade

Plus, no engine maker designs an engine for a single grade of oil either.

 

[tolian21]

Its long term use of non recommend weight of oil that can cause a problem

Then why in different countries the same exact engine has different list of allowed viscosities?

 

[tolian21]

We all know more than the engineers that designed our engines….right?

I am following Mexican owner manual for my Acura RDX that allows 5w-30, but the same manual in USA only has 0w-20. I am following the engineers that wrote Mexican manual. Is it wrong?

 

[Runalot]

Make it BITOGthicc and I'm in.

Just sayin'