Pat Goss' perspective on thicker oils

[hatt]

Originally Posted by Jackson_Slugger
I generally agree with Goss that most should use the oil spec'd by their manufacturer. But what does he think about the dealership tech-knobs that tell customers to needlessly use BG products when most manuals say using aftermarket oil supplements are unnecessary?

"Oh, now that's different..."

 

[Hall]

Originally Posted by hatt
The engineers don't write the owners manual.

Nope, they just just give the technical writers the details to include in the manual. You think the writers get to pick what oil viscosity they write in the manual ?

 

[Hall]

One of the few times I agree with him. He's always struck me as arrogant.... He's normally very much against DIY auto work too, suggesting only mechanics/technicians are qualified or capable of doing anything besides changing wiper blades or adding washer fluid to vehicles.

 

[dwendt44]

We all don't have new cars and drive like Grandma.
Higher mileage, some what worn engines benefit from thicker oil.
High performance also need thicker oil.

My 2¢

 

[Hall]

Originally Posted by Marco620
The oil the car was designed to use huh? Then that means it was operated the way it was designed to be operated. Which means driven the speed limit,not excessively idled,no aftermarket performance modification,etc.

Why do people think that automakers only test their vehicles on interstate highways, at a consistent ~65 mph, on a 50º F day vs testing them in the deserts while pulling a heavy load or letting them idle for days in Northern Canada for cold temperature testing ? They abuse their vehicles far beyond what owners eventually will. Everyone wants to think their vehicles are used under "severe" service conditions, but I'll bet the automakers laugh at those thoughts.

 

[CT8]

Originally Posted by ka9mnx
Yes, true, it was about 20 years ago. Then why did Ford back spec most of their engines back to 1993 when they had nothing to gain doing so?
Amsoil didn't actually not recommend 5w-20. They said if you choose to use a 5w-20 oil it should be a good oil (recommending, of course, their oil).
Not bashing what you said but it boggles my mind why Ford chose to back spec 5w-20 to 1993 engines. Amsoil produces a lot of good technical articles but there is a lot of marketing BS trying to convince readers their products are far superior than the competition.

Fuel mpg credits.

 

[CT8]

Originally Posted by Zaedock
98% of us here, are morons. *raises hand*

Morons? I doubt that,, suckers for marketing claims yes.I still smirk when AE Hass' oil writings were regurgitated as gospel fact here.

 

[hatt]

Originally Posted by hallstevenson
Originally Posted by hatt
The engineers don't write the owners manual.

Nope, they just just give the technical writers the details to include in the manual. You think the writers get to pick what oil viscosity they write in the manual ?

Obviously the writers do pick the viscosity since manuals for different counties many times say different things. Engineering doesn't change when you cross a border.

 

[Job]

Show is still on. As long as he doesn't call oil by weight he is ahead. Maybe he does but right now they have paused the reviews. They have a drive America episode or two now which actually was quite relaxing.Fell right to sleep.

 

[Supersonic]

Or dare I compare to the 'sealed transmission' and once the warranty is elapsed, the owner is inclined to go buy a new car because of planned obsolescence.

Summer months I may use a thicker oil depending on usage. I am not likely to exceed 5000 miles on oil change interval, and cringe thinking of the day that I have to buy a vehicle that has been on the 10,000 mile interval. End thinking out loud.

 

[shrooms]

Read the oil cap folks.

Done.

 

[Yah-Tah-Hey]

I seriously doubt the engine computer can detect the oil viscosity.

 

[Dfeeds]

Originally Posted by Yah-Tah-Hey
I seriously doubt the engine computer can detect the oil viscosity.


Some can, to a degree. DOHC cars or those that use oil pressure to change the cam timing have the computer set up to determine the oil viscosity based on how those components are reacting at a given temperature. So certain things, like cam timing, could be limited until the computer sees the characteristics that it's programmed to see as "ideal." This is something that could very easily be changed from country to country if there's a different oil viscosity spec.

 

[4WD]

Originally Posted by Yah-Tah-Hey
I seriously doubt the engine computer can detect the oil viscosity.


Who said it could ?

 

[John_Conrad]

start video at about 2:27 where pat eventually say's
"that increase in oil pressure can confuse the car computer"

in reference to variable valve timing.

i believe that is what yah tah hey is posting about

 

[LubricatusObsess]

Interesting MOPAR spec'd ONLY 5W-20 viscosity for the new Gen III HEMI when it was introduced in the early 2000's. I read at the time it wasn't for CAFE as much as the MDS system because they knew it was susceptible to oil starvation (wiping out lifters and cams). They needed flow, not lubricity. I owned one and made it to 100,000 miles without issue.

Now I own a 6.4L HEMI, and they spec 0W-40. Huh? I mean, who's gonna race a heavy duty pickup truck? Perhaps they want higher vis. for towing, but these oils shear down anyway. The HEMI's are MPFI, so don't contaminate oil early with the soot & fuel dilution of GDI. Nevertheless, it's still just a stoichiometric standard gasoline engine, so what gives with the 40 weight?

 

[OVERKILL]

Originally Posted by LubricatusObsess
Interesting MOPAR spec'd ONLY 5W-20 viscosity for the new Gen III HEMI when it was introduced in the early 2000's. I read at the time it wasn't for CAFE as much as the MDS system because they knew it was susceptible to oil starvation (wiping out lifters and cams). They needed flow, not lubricity. I owned one and made it to 100,000 miles without issue.

Now I own a 6.4L HEMI, and they spec 0W-40. Huh? I mean, who's gonna race a heavy duty pickup truck? Perhaps they want higher vis. for towing, but these oils shear down anyway. The HEMI's are MPFI, so don't contaminate oil early with the soot & fuel dilution of GDI. Nevertheless, it's still just a stoichiometric standard gasoline engine, so what gives with the 40 weight?


The pre-MDS HEMI spec'd 5w-30, when MDS came along they began spec'ing 5w-20, I don't recall any noise about oil starvation save that recent Uncle Tony video where he appears to forget that the lifter bores are pressure lubricated.

When the SRT version of the HEMI was developed, it spec'd a 0w-40, which, at the time, was Mobil 1 0w-40. These engines didn't have MDS. When the MDS version came out in 6.4L trim, both the MDS and non-MDS engines spec'd 0w-40 and this also carried over to the Hellcat mill.

When the lower specific output truck version of the 6.4L then came into production it carried over the 0w-40 spec from the SRT engine.

The MDS systems are the same on the 6.4L and 5.7L along with most if not all of the part #'s. The difference is in the programming.

 

[LubricatusObsess]

Ah....so I have a racing truck engine!

I figure no harm, no foul, but PUP 0W-40 is pricier. Yes, there is plenty more noise about lack of lubrication beyond Uncle Tony's infamous video rant (where he doesn't even see the oil galley supply holes in the lifter bores). RamForumz is full of it.

By the way - what does acronym LSPI stand for? I searched, but only found the acronym. Low Sulfur Pre-Ignition?

 

[buster]

He's not wrong, but there are nuances to this. The reality is, most if not all engines can be run on different viscosity grades. This is evident by some owners manuals which have shown that you can run anything from a 0w20 to a 5w40. In the U.S. and globally, 0w20's have become close to the norm due to fuel economy reasons. 0w20s are often made from good base stocks and additives.

In the U.S. where speed limits are generally no higher than 75mph, 0w20's are fine. Would that apply to speeds over 100 mph? I don't know.

Most engines are not as sensitive to viscosity as many think. There are driving forces that have lead to lower viscosity oils. I have no issue at all going with what the OEM recommends. Once I'm out of warranty, and the car ages, I also have no issue going up a grade.

Years ago I read an article about this and a GM engineer said that viscosity doesn't matter as much as most people think. There is a viscosity range most oils can operate within and that is found in the owners manual.

 

[ragtoplvr]

I have 2 cars that are seldom driven, both of them recommend 5W20 oil. I use 5W30 because of piston slap in one, *Ford 3.9V6 and the other a 2.5 FUSION will rattle for a few seconds if it sits a week or more. Despite what Pat says, I am still using them.

I think for my application, it is a good choice.

I also let them idle for about 30 seconds minimum after starting when I engage the AC so it has time to get the refrigerant moving before the compressor sees higher RPM.

Rod