CAFE and 5W-20 - The Truth

[Jaymus]

Originally Posted By: Drew99GT
Originally Posted By: Jaymus

I think it would work with a 30 or 40 weight.


http://www.allpar.com/mopar/new-mopar-hemi.html It's not just oil pressure. You can think all you want, but 5w-20 is required for the CDS to work properly.

Yet again, more proof that it's probably best to follow the manufacturer speced oil and not "think" you know better.


It says nowhere in that article that it is required. I see where it says "May not work", but no "required to work". You can use any oil you want as long as your pressure doesn't exceed 75psi when warm to allow the cylinder deactivation to work. A 5W-20 is not required like you think. You actually think a 5W-30 will destroy the engine? Of course not. You think a 5W-30 won't allow the cylinder deactivation to work? Nope, it will still work.

Again, "minimum and maximum oil pressure limits for cylinder deactivation and reactivation were established at 75 psi and 18 psi". It does not 'know' if you have something other than a 5W-20 in there. It just knows oil pressure, and goes by that. A 5W-20 would allow the C.D. to come into effect first, but does not mean a 30 or 40 weight won't work. A 5W-20 when cold is thicker than a 20W-50 when warmed up. So, why doesn't that 'destroy' or 'damage' the engine during the first 10+ minutes of usage? No need to try and get technical, it's all about the psi.

 

[Jaymus]

"Oddly, the new Hemi appears to use 5W20 motor oil - a specification which is expected to be widely adopted, but which is still not widely available. (In the Magnum R/T and 300C, 10W30 is recommended.)" Also quoted from your article. I'm not a Dodge man, but from my research, the same Hemi engine is in those vehicles, too. So, apparently a 5W-30 (or RECOMMENDED 10W-30) is not harmful to the engine.

 

[1sttruck]

Chryslers with Hemis are offered outside of the US, 5w20 isn't readily available and is not used, the cars work fine using thicker oils when driven typically harder then in US. Some report that the owner's manuals outside of the US say that it's ok to use a range of oils.

 

[Gary Allan]

Jaymus. The difference in cylinder de-activation, if viscosity dependent, would be altered in terms of onset of availability with heavier oils. Most driving events are 20minutes or less. It takes about that long to reach normalized oil temp ..and therefore visc. That's why 5w-20 oils were brought to the mainstream market to begin with. There was yield to be had in that time frame of usage with lighter oils.

btw- this quote, "75 psi and 18 psi" is suspiciously like the normal oil pressure spec for my jeep engines ..only inverted. 13-75lb @ 1600 rpm. That's the relief limit of my OEM pump max. It's the rating (in my case) of the stress limits of the distributor drive.

 

[Drew99GT]

Originally Posted By: 1sttruck
Chryslers with Hemis are offered outside of the US, 5w20 isn't readily available and is not used, the cars work fine using thicker oils when driven typically harder then in US. Some report that the owner's manuals outside of the US say that it's ok to use a range of oils.



Do they have cylinder deactivation outside the US?

 

[Drew99GT]

Originally Posted By: Jaymus

You can use any oil you want as long as your pressure doesn't exceed 75psi when warm to allow the cylinder deactivation to work.


Sure you can, but why then do owners report that the CDS doesn't work after they go to Jiffy Lube and get 10w-30 instead of 5w-20? Are you a Chrysler engineer?

Originally Posted By: Jaymus

A 5W-20 is not required like you think.


Yes it is. Go read the TSB and re-read the article I posted. Since you have no firsthand experience with the HEMI CDS, you have no clue what you're talking about - not to mention your knowledge of UOA (or lack there of).

Originally Posted By: Jaymus

You actually think a 5W-30 will destroy the engine? Of course not. You think a 5W-30 won't allow the cylinder deactivation to work? Nope, it will still work.


Do you have a HEMI with the CDS? If not, then you don't know. I'll base my opinion on the matter from evidence presented from Chrysler and owners of HEMIs with CDS, not some know it all on a motor oil forum. Owners report that it may work off and on and not smooth at all with oils other then 5w-20, or it won't work at all. If it's that much of an issue, why did Chrysler put a TSB out for it?

Originally Posted By: Jaymus

Again, "minimum and maximum oil pressure limits for cylinder deactivation and reactivation were established at 75 psi and 18 psi". It does not 'know' if you have something other than a 5W-20 in there. It just knows oil pressure, and goes by that. A 5W-20 would allow the C.D. to come into effect first, but does not mean a 30 or 40 weight won't work. A 5W-20 when cold is thicker than a 20W-50 when warmed up. So, why doesn't that 'destroy' or 'damage' the engine during the first 10+ minutes of usage? No need to try and get technical, it's all about the psi.


AGAIN, why doesn't the system work when thicker oils are used? It's not just oil pressure that affects the system. Like on many hydraulic VVT actuators, the orifices are so small where oil pressure activates the mechanism, that thin oil is required. The HEMI with the CDS has special collapsible lifters that operate the CDS. When thick oil is used, even at operating temperature, the oil can't pump up the lifters and the CDS won't work properly.

Stop acting like you know more then Chrysler engineers, cause you don't.

 

[peterdaniel]

Cylinder Deactivation in a HEMI is like decaf coffee or non alcoholic beer... Whats the point?

 

[JDD]

Originally Posted By: Mustang_Cougar
Originally Posted By: Liquid_Turbo
It's very possible that back in 97 they would have wanted to recommend an oil like 5w20, but couldn't, simply due to the lack of availability..


Yeah, that's what I thinking. Look at the Lima block for Ford...they've back spec'd that engine maybe all the way to the Pinto (just kidding). In the interim, nothing dynamic has really changed w/that block (other than stroking the 2.3l to 2.5). So, if 5w20 was widely available in the 90's, Ford would have used it; alas they couldn't.

However, that flies in the face of our accepted cynicism of all things big and corporate. A company like Ford saying they are doing this for the consumer's benefit (e.g., better gas mileage) is just not gonna be credible. And this in spite of the fact that here, on Bob's giant forum of oil, there isn't one single report of engine failure due to back spec'ing from 30w to 20w. But the speculation ran (or is trying to run once again) rampant...sort reminds you of old women in a knitting circle, no?


Uh----my mechanic (and friend) has fleet repair accounts, with one running all Fords and he says he has done 2 engine rebuilds both with bearing failures and both trucks had the 6 cyl. The company does all their own oil changes and used 10-30 oil. Oil spec was 5-20. Both trucks were below 80K miles. Anecdotal---sure. But to say there is not one single report of failure is careless. And BTW, your initial response to the original poster was in poor taste. The search feature is not that friendly. Civility should matter, not to mention patience with those less experienced on this site.
edit--friend says bearings were oil starved--

 

[Liquid_Turbo]

Originally Posted By: JDD
Originally Posted By: Mustang_Cougar
Originally Posted By: Liquid_Turbo
It's very possible that back in 97 they would have wanted to recommend an oil like 5w20, but couldn't, simply due to the lack of availability..


Yeah, that's what I thinking. Look at the Lima block for Ford...they've back spec'd that engine maybe all the way to the Pinto (just kidding). In the interim, nothing dynamic has really changed w/that block (other than stroking the 2.3l to 2.5). So, if 5w20 was widely available in the 90's, Ford would have used it; alas they couldn't.

However, that flies in the face of our accepted cynicism of all things big and corporate. A company like Ford saying they are doing this for the consumer's benefit (e.g., better gas mileage) is just not gonna be credible. And this in spite of the fact that here, on Bob's giant forum of oil, there isn't one single report of engine failure due to back spec'ing from 30w to 20w. But the speculation ran (or is trying to run once again) rampant...sort reminds you of old women in a knitting circle, no?


Uh----my mechanic (and friend) has fleet repair accounts, with one running all Fords and he says he has done 2 engine rebuilds both with bearing failures and both trucks had the 6 cyl. The company does all their own oil changes and used 10-30 oil. Oil spec was 5-20. Both trucks were below 80K miles. Anecdotal---sure. But to say there is not one single report of failure is careless. And BTW, your initial response to the original poster was in poor taste. The search feature is not that friendly. Civility should matter, not to mention patience with those less experienced on this site.
edit--friend says bearings were oil starved--


Well, this is where someone like FrankN4 would say he's been using 15w50 for everything with good results.

For me, the issue is clear. Stick to recommended until warantee. After that, use whatever you darn well please... and accept any ill consequences..(such as an apparently malfunctioning CDS system.)

It always pains me to hear about people trying to 'outsmart' engineers. Why would someone praise the engineering of say, a reliable Honda engine or proven Ford engine, only to simply choose another oil that is outside what the engineer's recommend??

As a professional practicing engineers, you are required to uphold a certain moral standard, as well as comply with SAE standards. CAFE would not cause a violation of SAE standard, but merely force an adaptation. I've posted a Honda research paper before outlining wear differences between 0w20 and 5w30. (No, not UOA based, but actual wear testing)

Did 0w20 cause more wear? Yes. But EXTREMELY small amount, still WELL BELOW acceptable limits. I repeat NOWHERE near the accepted limit.

Imagine if the entire nation used recommended oil as spec'd. We'd be saving millions and millions of MPG collectively.

I'd even go as far to say that is your moral obligation to use the recommended oil and help meet CAFE standards.. the same way you are obligated to turn off the light when you leave a room, to save energy.

 

[Gary Allan]

Quote:
Why would someone praise the engineering of say, a reliable Honda engine or proven Ford engine, only to simply choose another oil that is outside what the engineer's recommend??


While I generally agree, the engineer accounts for a very broad user base ..of which, admittedly, most of those who try to out think him reside within. One may, however, find themselves in a service duty that the engineer could never be granted the latitude to spec for ..even if the "K-I-S-S" mandate that they're governed by allowed it.

"I'm a priority courier and run Death Valley twice daily @ WOT from one end to the other loaded to the gills with the air on. What visc can I use that won't change itself through my PCV system?"

 

[tdi-rick]

Originally Posted By: Drew99GT

Do they have cylinder deactivation outside the US?


Yes.
I'm wondering what they use for oil here. Might ring the nearest dealer, could be interesting.

 

[Liquid_Turbo]

Originally Posted By: Gary Allan
Quote:
Why would someone praise the engineering of say, a reliable Honda engine or proven Ford engine, only to simply choose another oil that is outside what the engineer's recommend??


While I generally agree, the engineer accounts for a very broad user base ..of which, admittedly, most of those who try to out think him reside within. One may, however, find themselves in a service duty that the engineer could never be granted the latitude to spec for ..even if the "K-I-S-S" mandate that they're governed by allowed it.

"I'm a priority courier and run Death Valley twice daily @ WOT from one end to the other loaded to the gills with the air on. What visc can I use that won't change itself through my PCV system?"


Unless most of us run WOT on the track daily, most of us would fall under the "broad user base" won't we?

As for the hypothetical priority courier..In a typical owner's manual with the viscosity recommendations,

I'm not sure, but how hot does it get in Death Valley? 50? Just run the recommended oil as you would in severe service and call it a day?

You're describing a rather unique situation, but it sounds like it could still be under the 'broad user base..'.

 

[Gary Allan]

Quote:
You're describing a rather unique situation, but it sounds like it could still be under the 'broad user base..'.


It would in fact mimic marine usage in no marine environment that I can think of. Yet ...assuming a like power plant (let's say an SBC) in marine usage would not carry the same max temp spec's ..even at lower spec temps.

Yes, this is unique. That was the whole point of the suggested scenario. Would it be STUPID to trump your recommendation in a unique situation? I say, not necessarily. Does just about everyone think that they're situation is unique and requires traveling out side of the lines? Yep. Do most of them? Nope.

 

[1sttruck]

"I'd even go as far to say that is your moral obligation to use the recommended oil and help meet CAFE standards.."

That would be like the people who bought the cute little furry cat figurines afew years back, only to find out that the figurines were being made from real cat fur :^)

Makers could actually develop and sell vehicles that get better mileage, as in many miles per gallon, but instead companies like Ford chose to resort to a bag of tricks that included using 5w20, getting very small to unmeasurable mileage improvements in order to keep selling high margin trucks, SUVs, and cars and vans with V6 and V8 engines that get poor mileage.

The EPA seems to limit the mileage that makers can claim from using 5w20 oil, in part due to how much 5w20 oil is actually being used (so that more trucks and SUVs and such can be sold). The makers seem to have punted the figure for the amount of 5w20 being used to the lubrication industry, and evidently that's where it sits. That is why there is such hard sell on 5w20 by makers.

 

[tig1]

1sttruck,

Your are talking in circles.First you say we have a moral obligation to use 5-20 oil to meet CAFE standards, then you critize Ford for calling for 5-20 to help meet CAFE standards, saying it's a cheap bag of tricks, and a unmeasurable mileage improvement. What's up with the double talk? Also some people need trucks for work or towing. Some need vans or SUVs to transport their families. It's our right.

 

[1sttruck]

"Your are talking in circles.First you say we have a moral obligation to use 5-20 oil to meet CAFE standards,"

Quoted text is identified using quotes.

 

[TallPaul]

I think the moral obligation thing was just a quote that 1sttruck was respondig to.

Yeah, some moral obligation. The auto companies do 5w20 to avoid paying CAFE fines. Who could really say CAFE is morally right anyway? I don't see it in the Ten Commandments.

 

[Bryanccfshr]

I don't see morality in the book that the ten commandements is taken.

 

[Liquid_Turbo]

Ooo. Better steer clear of this religion talk (which is forbidden in the rules of the board)

I was more intending to focus the individual doing their own part. If a million cars saved 1MPG, that's a million MPG that's being saved.

Just use 5w20 (as warranty requires, and call it day). Everyone speaks of CAFE as this evil thing notion created to reduce your engine life for the sake of reduced gas usage...simply not true.

 

[Gary Allan]

CAFE isn't evil ..nor are 20 grade oils.

I'd say our biggest "pig" aspects are emissions and safety gear. Unleash the engineers without those two anchors and you get plenty of economical cars ...on 5w-20 or whatever.