Ford's write up on their reasons for use of 5W-20

[Rodbuckler]

This is from their fleet newsletter. It pretty much summarizes all of the reasons for the use of 5W-20 that we discuss here. It also puts the "only for gas mileage" theory to bed.

https://www.fleet.ford.com/FFH/Rental05_23_06.asp

"Why 5W20 Oil?
Some customers are reluctant to follow Ford's recommendation to use 5W-20 oil in their engines based on the incorrect assumption that Ford and other Auto Manufacturers only recommend 5W-20 oil in order to increase fuel economy. Using 5W-20 oil can increase fuel economy by about 6/10ths of a percent compared to 5W-30 and more if you are currently using a higher viscosity oil. This equates to an additional savings of 125 million gallons per year when used in all applicable Ford vehicles. Since its introduction in the 2001 MY, 5W-20 oils have saved up to 640 million gallons of gasoline in the U.S. or an equivalent 5.6 million metric tons of carbon dioxide emissions.

5W-20 oil is a thinner oil with lighter viscosity that creates less drag on the crankshaft, pistons and valvetrain. Additionally, the oil pump can pump thinner oil more easily, improving oil circulation. Any increase in fuel economy may not be noticed by the average motorist. Machined internal engine parts are more precise than the parts of 20 years ago. This means that clearances between moving parts are smaller and more exact. Thinner oil such as 5W-20 can flow more freely through the engine while still filling the spaces. Thicker oil is harder to push through the spaces between the parts. This causes the oil pump to work harder, which in turn increases oil pressure while simultaneously decreasing oil volume. A lack of oil volume results in a decrease of lubrication and cooling, which may decrease engine part life.

The lighter viscosity of 5W-20 oil flows faster at start-up compared to higher viscosity oils, which helps reduce engine wear in critical areas by lubricating parts faster. Valvetrain components at the top of the engine require immediate lubrication at start-up.

Oil additives are not recommended as noted in the owners manual. The American Petroleum Institute (API) certifies that oils such as Motorcraft 5W-20 already contain the necessary additives for friction, detergent, etc... The addition of additives may interfere and react with the additives already present in the certified oil."

 

[buster]

Thanks for posting this. I agree with the article. When you also see how well tested Ford/Dodge/Honda put the oils through, it shouldn't be a concern at all.

 

[miked2]

Some of our members believe Ford specs 5w-20 just to increase gas mileage.
My question always was, why would a manufacturer recommend something that could cause potential engine damage? Your post certainly answered that.
Thank you!!

 

[BUDSHAD]

Great post thanks.

 

[JohnBrowning]

miked2, If you did not change the oil at all you simply toped off as needed the car would in most cases make it well out of the warranty period. So even if and I am not saying it does but if 5W20 cut the engines life usefull emission legal life in half it would not matter. Lets say that the engine is designed to provided 75% of it's origanal power output, consume not more then 1 quart of oil per 700-1000 miles, and pass emissions with only routine maintence for 300,000 miles. Now lets say that they determined that useing 5W20 would cut that number by 30%-50%. That is still 210,000-150,000 miles before any potenial problems would arise. This is more then enough time for the first owner to fill he either got his money worth out of it or to trade it in. So it really would not affect the OEM's reputation much or any at all. Few people own their vechiles that long especialy with all the leaseing going on! Most people in America still get excited if their car has 120,000 and it still runs well. A lot of people still consider 100,000 miles as high milage! If you do not know that you could have extended the quality and life cycle of the engine by useing a 5W40 for example then what have you lost?

 

[pitzel]

Its pretty hard to find anything 'thinner' than 20W-50 in Costa Rica (lots of straight weight 60 on the shelves), yet the petrol-fired cars there all burn lots of oil and smoke badly.

Maybe there is a correlation...maybe not

If I didn't have a 20 year supply of Esso XD-3 0W-30, I'd consider using 5W-20 too.

 

[Blue99]

A large corporation such as Ford Motor company has many employees with different backgrounds, some technical, some not so technical.

Understand that the above article is more than likely written by someone in the marketing department who is just editing & condensing some of the more popular folkore regarding the myths of 5W-20 motor oils.

Note that no technical references are quoted, as would be the case by a true senior level degreed professional in the mechanical/chemical engineering or triboligist fields with technical writing experience.

Disclaimer - I'm not a thick oil fanatic and would use 5w-20 if I owned a Ford vehicle.

But I object to having to swallow some of these 5W-20 myths:

quote:

---

Machined internal engine parts are more precise than the parts of 20 years ago. This means that clearances between moving parts are smaller and more exact. Thinner oil such as 5W-20 can flow more freely through the engine while still filling the spaces. Thicker oil is harder to push through the spaces between the parts. This causes the oil pump to work harder, which in turn increases oil pressure while simultaneously decreasing oil volume. A lack of oil volume results in a decrease of lubrication and cooling, which may decrease engine part life.

---

So if the clearances are tight and a 10.5 cSt 5W-30 has insufficient flow compared to a 8.5 cSt 5W-20 - (note that we are comparing full operating temps at 100C) - what happens with a cold start in the northern climates and the temp is subzero and the 5W-20 is 200 times thicker at 2000 cSt?

And it takes 20 minutes of driving before the crankcase oil arrives at 100C and 8.5 cSt? Does the engine explode due to an oil 200X thicker than the "clearances" and pump require?

And how does Ford explain that 5W-20 was back-spec'd clear into the early 90's on some engines.
These engines had "tight clearances" and magically survived on 5W-30 for 6-10 years til the early 2000's when Ford waved the magic back spec wand?

Give me a break!!!

Go to the UOA forum & search on the Ford 4.6L engine UOA's reported by MnGopher. He has a detailed UOA history of running 5W-20, 5W-30 and 5W-40 in his F-150 pickup.

Yeah, the guy writing the 5W-20 article with the "clearances" excuse as his justification for 5W-20, would just about have his head explode trying to explain a low wear metal UOA with 5W-40 in a Ford 4.6L engine.

 

[Raven18940]

viva la 40 weight

 

[hominid7]

A 5w20 will flow faster at start-up, lubricate better, and perhaps cool better than a 10w40 or a 20w50 in some engines, but i'm not ready to believe that it will flow better at start-up, cool better, and lubricate better than a 5w30 or even perhaps an energy conserving rated 10w30.

My Mazda owners manual says i can use 5w30 from -22*F up to 98*F and says i can use 10w30 from -13*F and above. In it's old Ford Probes with the same Mazda/Porsche designed V6, Ford has back-spec'd it to allow 5w30 year-round regardless of climate. Mazda, on the other hand, has not changed their recommendations. So i'm not sure who i should believe. I've used both 5w30 and 10w30 in my car and I go back and forth as to which performs better. Perhaps it's too close to call. My choice of filter may make more of a difference than choosing 5w30 over 10w30 or vice-versa.

5w20's certainly have their place, but a one-size-fits-all oil kinda makes me nervous. I've always been of the mind set that ones oil should be chosen with ALL the factors in mind.

 

[vad]

More B*S* from Ford.
There was a TSB published where FoMoCo clearly stated that the whole reason for the 5w20 grade switch is a marginal improvement in fuel economy.
That's all.
Now they're inventing some pleasable reasons to cool off the wandering minds when questioned why 5w20 is not specced for the rest of the world in exactly the same engines.
Go to this Castrol U.K. site. In the "Tools" section click on "Which oil should I use?" button and search for a model of interest.
If it specced for use with 5w20 in the states, chances are that it's specced for something thicker across the pond.
Like the Brits wouldn't want to squeeze out every available mpg (with their gas prices!) and get better engine protection, all the same time.

 

[GrtArtiste]

"Thinner oil such as 5W-20 can flow more freely through the engine while still filling the spaces. Thicker oil is harder to push through the spaces between the parts. This causes the oil pump to work harder, which in turn increases oil pressure while simultaneously decreasing oil volume. A lack of oil volume results in a decrease of lubrication and cooling, which may decrease engine part life."

My question is...are there measurable differences between use of 5w20 and 5w30 which would favor the use of 5w20 for these stated concerns? My guess is that perhaps it can be measured in favor of 5w20, but that the difference so small as to be almost meaningless. I'd love to be proven wrong. Any takers?

"The lighter viscosity of 5W-20 oil flows faster at start-up compared to higher viscosity oils, which helps reduce engine wear in critical areas by lubricating parts faster. Valvetrain components at the top of the engine require immediate lubrication at start-up."

At start-up, aren't 5w20 and 5w30 virtually the same? If no, then please state why. If yes, then 5w30 is just as suitable as 5w20 in this area.

GrtArtiste

 

[michaelc80]

Is there any evidence that using a 5w20 in an engine that specs it is harmful? If not, then why all the hoopla about it? Or is it just that a lot of people can't get past their "thicker is better" mindset?

 

[GrtArtiste]

quote:

---

Originally posted by michaelc80:
Is there any evidence that using a 5w20 in an engine that specs it is harmful? If not, then why all the hoopla about it? Or is it just that a lot of people can't get past their "thicker is better" mindset?

---

Speaking only for myself...I'm not trying to push "thicker is better". I'm sure the 5w20 oil does just what it's supposed to do. Maybe I'm just dense, but I have yet to hear a valid argument that provides understandable reasons why a 5w30 SHOULD NOT BE USED. Tell me what it is and I'll be happy to oblige. Until then, 5w20 is just a change that makes little, if any real difference.

GrtArtiste

 

[clg305]

Hold on let me get into my flame proof suit here... OK its a ford it will fall apart long before the oil makes a difference to the engine. Incoming!!!!

 

[Cicero17]

I totally agree. The rest of the car on a Ford, Dodge or GM will fall apart around the engine unless the engine is abused. I have never had an engine problem although I don't keep cars very long, the last two only had 125K miles on them. Our Grand Voyager was falling apart around the engine and transmission when I sold it to a friend over 2 years ago. He has had to weld and paint and repair on the body, but the engine and transmission are as strong as ever. I fed that car dino oil every 3,000 miles and kept the transmission maintained. Did I mention he is a real estate agent. Now I use Mobil 1 at more extended drains. I have 5w30 in the Odyssey for the summer.

 

[Rodbuckler]

I've found my Fords to be very durable and reliable with minimum repairs required. I have four of them with combined mileage of 934K. My '96 Mustang GT with the 4.6L has 215K on it, and looks, runs, and drives like a new car. There is absolutely nothing wrong with it whatsoever. I drive it hard and put alot of miles on it each month.

I tried alot of oils in the 4.6L, and my observations are exactly as stated in that article for the fleet managers. The engine runs perfect under all operating conditions with the 5W-20, with amazing performance on cold startup. The 30 weight oils drag my engine down noticeably hot and cold, and give valvetrain noise on cold start. I tried GC (a thick 30) and had to drain it out immediately for fear of losing the engine.

There is no way a 30 or 40 weight will protect my engine better than the 20 weight. The engine is designed for the 20 weight. Also, the kinematic viscosity doesn't tell the whole story about how the oil behaves in the system. The 4.6L runs better cold with the 5W-20 than it does hot with the the GC.

 

[Iain]

Rodbuckler wrote:

quote:

---

I've found my Fords to be very durable and reliable with minimum repairs required. I have four of them with combined mileage of 934K. My '96 Mustang GT with the 4.6L has 215K on it, and looks, runs, and drives like a new car. There is absolutely nothing wrong with it whatsoever. I drive it hard and put alot of miles on it each month.

I tried alot of oils in the 4.6L, and my observations are exactly as stated in that article for the fleet managers. The engine runs perfect under all operating conditions with the 5W-20, with amazing performance on cold startup. The 30 weight oils drag my engine down noticeably hot and cold, and give valvetrain noise on cold start. I tried GC (a thick 30) and had to drain it out immediately for fear of losing the engine.

There is no way a 30 or 40 weight will protect my engine better than the 20 weight. The engine is designed for the 20 weight. Also, the kinematic viscosity doesn't tell the whole story about how the oil behaves in the system. The 4.6L runs better cold with the 5W-20 than it does hot with the the GC.

---

Well said.

I totally concur. I've run Mobil 1 5W-20 in my 2001 Taurus since beginning of year. My initial OCI of Mobil 1 was of 5W-30. In retrospect, the difference in performance between them is amazing. 5W-20 is more efficient.

Thanks for posting the article, BTW. It confirms my observations of the past few months.

 

[ewetho]

Well now let us just throw in the MONKEY wrench NOW!!!!

Ready.....

Ford Mustang, Explorer, Rnager 4.0L -- 5W-30
Ford GT, Mustang GT500 -- 5W-50

By Spec!

Flame suits on!!!!

Now we see why everyone is so confused!!!

 

[Gary Allan]

quote:

---

Originally posted by Blue99:
So if the clearances are tight and a 10.5 cSt 5W-30 has insufficient flow compared to a 8.5 cSt 5W-20 - (note that we are comparing full operating temps at 100C) - what happens with a cold start in the northern climates and the temp is subzero and the 5W-20 is 200 times thicker at 2000 cSt?

---

What's just as funny is that the other end of the scale is ignored just as much. If you're towing up an 8% grade with 40 weight ..and you're oil temp is pushing 250-260F ..what weight isn't destroying your bearings ....20 weight?? They ignore that the side effect ..or remedy is typically a shortened OCI...yet feel fully confident that, at peak hp output, max torque output, that 20 weight oil is fully protecting their engine ..with all of its "designed for thicker oil clearances". They just don't know it. Now the common counter arguement is that, in the same situation ..an oil that started out a 20 weight in the same situation would be real thin ..and this would be true ..but what both examples depict (20 weight in sub 100C and 40 weight in 100C+ temps) is that there is a very broad sliding scale that all viscosities function at 100% reliability in virtually all situations for a variable amount of time. The insults to them don't necessarily negate their usage ..but shorten their life span in the face of the severity of the service.


And I DO think it's all about fuel economy. Why is this such a shameful goal? If it wasn't. If there was nothing to be gained here ..why go to all the trouble to engineer a durable enough product to do the task? Why not just stay with our generic offerings that were cheaper to produce? The "trick" to the whole thing was to achieve that added fuel economy without having any shortening of the lifespan of the engine.

That, they seem to have appeared to achieve.

[ June 17, 2006, 01:32 PM: Message edited by: Gary Allan ]

 

[vad]

quote:

---

Originally posted by ewetho:
Ford GT, Mustang GT500 -- 5W-50

By Spec!

---

If you follow Ford's logic, then those engines must be total junk.

With such huge clearances and unprecise engine parts, they require 5w-50.
The oil pumps must be so overstressed they need to be replaced every oil change.

BTW, what all of you think about the Euro engines.
What's the reason 5w-20 is not being pushed over there?