5w20 or 5w30

[crazyoildude]

Just curious why does ford spec. 5w20 for all their engines and 5w30 for the v6??
Also how many of you are using 5w30 in an engine that recommends 5w20..
i posted this in the oil filter section by mistake..

 

[tig1]

I have used 5-30 in my Fords. At preasant I am trying 5-20 in the Fusion. 5-30 won't hurt Fords at all.

 

[JustinC25]

I have run 5w20 in my Windstar 3.8 since I got it, except for when the dealer changed the oil the first time to bulk 5w30, and I called them out on it. But I didn't feel like waiting another 45 minutes for them to change it again. So I ran it for 3k, and everything was fine. Here I am 53k later and I haven't had a lubricant related issue yet. If the 5w30 was going to hurt anything, it would have happened by now. 5w30 in place of a 5w20 in a Ford won't hurt it.

 

[EricZoom]

Just curious why does ford spec. 5w20 for all their engines and 5w30 for the v6??


The V6 Duratec in my mazda6s specs 5w20, not 5w30. I actually use Mobil 1 0w20 in my car, and that engine seems to love it.

 

[Nick R]

He must be referring to the 4.0L V6. It is the only Ford engine that does NOT spec 5W-20, so there must be a good reason for it. Use whatever is specced.

 

[JohnBrowning]

No oil recomended by an OEM is going to harm the engine but it mightnot be the best fit for the application either. OEM recomendations take a lot of thingsinto consideration not just what is best for the engine!

 

[Sunabozu]

the 4.0 is a 20 year old block design, the clearances are not as tight as the modern designs.

 

[Zaedock]

Originally Posted By: Sunabozu
the 4.0 is a 20 year old block design, the clearances are not as tight as the modern designs.


Completely untrue.

Let's not turn this into another 20 vs 30 thread.

I'm just say'n.

 

[Sunabozu]

the 4.0 block has not changed since the early 90s, and the cologne engine family dates to 1968.

The reason it calls for the heavier oil is because it's an old design that isn't as tight as modern ones, it needs the thicker oil.

 

[Zaedock]

Originally Posted By: Sunabozu
The reason it calls for the heavier oil is because it's an old design that isn't as tight as modern ones, it needs the thicker oil.


Wrong again.

 

[crazyoildude]

ok so what is untrue? What is the reason? I asked three of my top engine guys here at the shop and got three different answers
And a few who cares...

 

[Sunabozu]

oh, i'm sorry, do you have some ford engineer knowledge you'd like to share with the class?

 

[beast3300]

I heard two reason for the 4.0 not using 5w30. One was because it was fuel efficient enough with 5w30. The other reason I heard is because the oil pump isn't good enough to pump 5w20. I don't know the true reason but run what's on your oil cap.

 

[modularv8]

Ford engines requiring 5w20 are designed to have higher flow rates, as well as, other lubrication system design changes. As for the 4.0, Ford's/Motorcraft's answer is this:

"Some of our carryover Engine Designs are not yet completed with 5W-20. For instance, the 4.0L engine's oil pump must be redesigned for more oil flow before 5W-20 can be used. As we change engine designs, we will recommend 5W-20. Some engine designs will never be able to accommodate 5W-20."

 

[Zaedock]

Originally Posted By: Sunabozu
oh, i'm sorry, do you have some ford engineer knowledge you'd like to share with the class?


It has nothing to do with Ford, it has to do with facts. This site is (or was, lately) a good source for facts. The fact is, that engine clearances have nothing to do with being able to run 20 weight oils.

It's one thing to post an opinion or educated guess on a subject, but to post something finite because that's what everyone seems to think, is wrong.

Sunabozu, please forgive my inital abrasiveness as I'm not trying to start a pee pee match. I'm just tired of hearing that overused excuse.
I'm a Jeep guy specifically, but am overall a long time automotive enthusiast with engine, transmission, and axle rebuilding experience. Suffice to say, I thought you would find it interesting to know that my old F134 in my 1959 CJ5 has tighter clearances than the 5.4L Modular in my F150.


Crazyoildude, here's my educated guess on your 4.0L Ford question. The ability to use a 20 weight oil in all climates has to do with the engines management system and vehicles ability to keep the oil IN GRADE during use. Therefore, IMO, Ford determined that the 4.0L's cooling and/or oiling system was not able to maintain the oils integrity in all testing scenarios (high temp, IMO). As a safety factor, they prescribed 5W30.

 

[modularv8]

That's sounds about right. Ford's 5w20 engines are designed to have higher capacity oil pumps, sumps, and cooling systems in order to have improved control over oil temperatures.

 

[Mustang2008Z]

5W-20 was specified for all Ford V-8 Engines to meet the U.S. EPA CAFE Standards as to mpg. The 5w30 was specified for the V-6 Engines for CAFE mpg, which includes the 3.8/4.0 engines.

So that Ford could avoid any wonderful fines/money that would have gone to EPA for failure to meet CAFE Standards.

Coffee..Anyone?........lol

 

[Bryanccfshr]

Originally Posted By: modularv8
Ford engines requiring 5w20 are designed to have higher flow rates, as well as, other lubrication system design changes. As for the 4.0, Ford's/Motorcraft's answer is this:

"Some of our carryover Engine Designs are not yet completed with 5W-20. For instance, the 4.0L engine's oil pump must be redesigned for more oil flow before 5W-20 can be used. As we change engine designs, we will recommend 5W-20. Some engine designs will never be able to accommodate 5W-20."


Quoted for accuracy.

 

[crazyoildude]

My opinion is the 5w20 is supposed to stay in grade longer than the 5w30... Also the 5w20 is a better oil from better base stocks... Overhead cams get quicker lube with lighter oils at any temperature..Lighter weight oils run cooler that thicker oils in most cases, lighter weight oils have less drag on the crankshaft and thus gives the engine slightly more power and gas mileage.. Then there is the cafe thing im sure had a little to do with it.. Remember the engines in the 20s 30s and 40s used 20w
I have heard about the oil pumps on the 4.0 engine also as one of the reasons not to use 20w but im still not sure and we rebuild them.... one of my guys still uses 10w40 in his older engines.. One mechanic i know who owns another shop about 5 miles from ours uses only 20w50 year round in his chevy 350 and thinks everything else is way to thin he is a very good mechanic but we butt heads on his thick oil beliefs all the time..

 

[roadrunner1]

one of the main reasons for the 5w30 spec on the 4.0 v-6 is ford was having trouble with the cam followers with 5w-20 on this particular engine, which may be attributed to oil pump/ oil flow i don't know. i own a'99 v-6 3.8 that was back-speced to 5w-20 and thats what i run in it, without hesitation.