No, I do not believe that 5w-20 is bad, just not as good as a 10w-30 in your location.

 

Here is an oil test conducted at the U of Michigan in cooperation with Lubrizol and GM:

http://me.engin.umich.edu/autolab/Pu...e/P2002_03.PDF

You might be interested in a couple of conclusions. For example, in low to mid speed and load applications in the test small diesel engine, 30w actually gave better fuel economy than a 20w:

Also, for all those people who claim syn gives better fuel economy than dino:

 

One other thing I failed to ask about but want to get clear in my mind:
I seem te remember most UOA's I have seen here for 5W20 tend to indicate an drain interval of 3K should be maintained, while dino 10w30 seems very content w/ 5K drain intervals.
Answers or comments?

 

I don't know about on this site but what I've seen on bobistheoilguy the Ford spec'd 5W-20 easily can go to 5,000 miles in an engine that was spec'd for that oil. In fact the Ford spec'd SL rated 5W-20 has to meet tougher standards than SL rated 5W-30 and 10W-30 oils. At this point in time it's actually a higher quality oil. Old prejudices and myths die hard .

Whimsey

 

I agree and admit that I might be guilty of that here in this case.

But . . . .

A 20w is still a 20w and a 30w is still a 30w.

A 20w is not as thick as a 30w. If it was, it wouldn't be a 20w, it would be a 30w.

So, in my mind, this isn't a question of comparing base oils or additive packages. Nor is it a question of comparing an API SG oil with an SL or even an SM. It's a question of do you want to run a 20w oil or a 30w oil. It's not rocket science.

If I lived in the Great White North, I would not have a problem running a 20w. But it's friggin' hot down here in the summer. I am much more comfortable running a 30w.

 

On an OHC engine like the Modular's I might be hesitant to go with the 10W30, but we're talking 4.2 V6 here. A stroked out Essex motor. Did the 3.8's of old recommend 5W20? Look and find out what the old Supercoupe's recommended for lubricant viscosity. If it recommends 5W20 then I'll shut up. The 3.8SC motor is the same as the 4.2 save stroked out pretty much. Maybe these days the 4.2 has a different intake or something..but essentially the same.

 

I'm not even sure 5W20 was available for the "3.8's of old."
Matter of fact, was 5W20 available in 1997 when the 4.2 was introduced? Introduced in '97 means it was probably on the drawing board in '95. Did Ford design the 4.2 for 5W20, or did 5W20 come along after the fact?
I'm going to ask anybody in the 4.2 forum, who owns a 97 model, to check their owner's manual for oil reccomendation.

 

Well, this certainly got lengthy.
Inregards to NASCAR, the individual teams run their own brew of lube depending on the track they are running. Long tracks with extended WOT will see a higher viscosity oil than a short track with off and on throttle. They use a high enough viscosity and film strength that there is not much of the engine left at the end of the race maximizing the output of the engine. No team that I am aware of uses anything in the 40w-50w.

Brian, as I remember correctly, your 4.2 has well over 100,000 on the odometer. Since you have been using the Xw-30, I wouldn't change. You may see a drop in oil pressure because the engine is "broke into" the heavier weight oils. Considering the UOA's you have posted, the combination of oil and filter is better than most. If you have a new 4.2 and it has less than 25,000 miles on it, I would suggest changing to the 5w-20. Also, the 5w-20's are holding up quite good at the 5,000 mile mark.

Rusty, drag racers use a higher viscosity oil because of the expected fuel dilution which is going to happen with any fluid they use. You are also thinking that as the viscosity goes up, so does film strength. It does providing you are talking about the same basestock but the 153-H oils are not the usual dino basestocks. Your favorite Mystic 20w-50 compared to M/E's new fatty acid ester basestock for instance, the M/E ester has 600 times the film strength at 0w. You are not comparing apples to apples when comparing a dino to a blend.

jshira, API could care less about fuel mileage, they are all about emmissions. While ZDDP is on the cutting block, newer F/M's and EP's are on the growth list. We are also seeing more and cheaper esters being produced that by todays standards are incredibile. All basestocks have been getting better. The Gp II of three years ago is old world technology today. There have been some tremendous gains in the lube industry. In regards to the U of M study, my ladyfriends sister worked that project. I am aware of the test criteria. You may want to investigate the test procedures before believing in full any outside reports. But the magic question for you is: why do you think it gets so hot in North Texas? Come on down where I'm at- I'll show ya hot. There are days when I get up at 5 AM and it is already over 90 or I guess I should say- it has cooled to 90. It ain't hot up there, it's hot down here.

Stormin Texan, if you do a search here, I have posted the test criteria for the 153-H speced oil. By comparison to the other oils, it is magical.

Is there any predudies concerning oils? Probably more than religion. Old habits die hard. How many times have you read "Well, my daddy used Slapoline for his cars an they never wore out" OR " I have been using Upchuckstic since I was just a kid and it has always done a good job". Listen folks, if you bought your favorite brand of oil in January 2004 and went to buy it today, IT AIN"T THE SAME STUFF! The lube industry has been more dynamic in the last 5 years than all of the years combined. Newer and better formulations, newer and better friction modifiers, newer and better basestocks, the list is endless. But, you the consumer are the winners.

 

Here is the page right out of the 1997 F-150 owners manual:

 

The paper is pretty complete in its description of how the tests were conducted and all of the results.

The problem with oil is that there are no independent, head-to-head tests. Well, there is the CR test, but people who disagree with it find all kinds of faults.

Of course, there are the published Amsoil tests. I believe those like I believe the infocommercial on making $$millions$$ in real estate without investing any of my own money.

So, you read what you can find. Maybe it all has some flaws, but most of what is available contradicts big oil's advertising messages and what "grandpa always did".

 

Flash,
This HAS gotten lengthy. But, it has remained interesting and civil - and that (IMHO) are the very reasons it has gotten lengthy!
Yes, at 138,000 miles, I guess my 4.2 is sufficiently "broken in" on 10W30 now. I don't want to be guilty of cutting off my nose to spite my face. I intend to stick with the 10W30 and Motorcraf FL400S.

Jeff,
Thanks for the owner's manual info. That answers one question in my mind. It would appear that the 4.2 was NOT designed to use 5W20. The 4.2 is a pretty standard push rod motor that, in my case, seems to like 10W30.
It appears 5W20 was built to help Ford's CAFE numbers. It is a great oil, but not one that should be sold as being the oil "your engine was designed to use".
If one argued the 4.2 was designed for 5W30, that begs the question: just how DOES one design and engine ot use 5W30 as opposed to 10W30??? The differences, I would guess, are negligible except in very cold weather at start-up. And even then, is there THAT much difference bewteen 5WXX and 10WXX ?

Here's my gut feeling:

a) the 4.2 is an engine whose ancestors were designed and manufactured in an era of 10W30. I suspect the 4.2 carries the lineage and remains - at heart - a 10W30 engine. 5W30, I suspect, was suggested for fuel mileage reasons (CAFE).
b) Ford had 5W20 special built to meet the demands of existing, and future families of engines. The oil was needed to help with CAFE numbers.
The oil was built, it is a great oil, but the 4.2 wasn't designed for 5W20. In fact, it might be a little more accurate to say that 5W20 was "designed" for the 4.2 (and other engines as well).

There is ample data to support chosing a quality oil, be it 5W20 or 10W30, will provide good protection.
Perhaps the simplest rule-of-thumb in my book would be:
Live where it tends to get really cold: run 5W20.
Live where it tends to get really hot: run 10W30.
But even that could be argued.

Best rule of thumb: It's YOUR truck. Run whatever oil you want to!

 

This discussion has stayed civil because we have not been discussing Brand A versus Brand B or dino versus syn. That has not been the issue.

In my mind, the issue is what weight do you want to run, in whatever brand and quality you want to buy.

While I may be stuck in the past, I still believe that in 100+ temps, a 30w is better for your engine than a 20w.

As a side note, the owners manual for my 1948 Dodge pickup recommends straight 30w in the summer and 30w cut with kerosene in the winter. So I guess that I have progressed a little bit and am not living entirely in the dark ages.

 

BrianA,

I agree with you. I feel most comfortable using 5W-20 oil in an engine spec'd for it from NEW. I have a 2002 F-150 with the 4.6 V-8 and have used Motorcraft 5W-20 since new and my one UOA was really good. I'm going to have another one done this next oil change. I also have a 1996 Ford Contour with the 4 cylinder 2.0L Zetec engine, 5 speed manual tranny and factory alloy wheels and wide tires, my "poor mans BMW" . It came spec'd for dino 5W-30 oil. I've been using various "synthetic" oils, 5W-30 and 5W-50. And by the way it likes 5W-30 over 5W-50. Even though Ford has said it's now ok to use 5W-20 I'm not using it but sticking with 5W-30 synthetic/semi syntetic. I'm now using Schaeffer's # 701, a semi-synthetic 5W-30, that seems to perform every bit as good as Mobil 1 for me and is usually less expensive. But If I was to use a "dino" 5W-30 I'd seriously consider the Ford spec'd 5W-20 over a "regular" dino 5W-30 oil. By the way, all hail to civility .

Whimsey

 

A little reading about 5w oils:

http://www.imakenews.com/eletra/view...+f0+106+&u=lng

Also read here about concerns that 5w-20s will increase oil consumption in older vehicles:

http://www.imakenews.com/eletra/view...2f4+2f5+&u=lng

 

Flash, I can see where you're coming from now. By using a different material (esters) with a higher film strength, they could go to a lower weight oil. I dont think you made it clear. To me it looked like you were saying that lower viscosity oils had a higher film strength, which didn't make any sense. One of those WTF things.

You showed the comparison of film strength at 0w. When was the last time my oil was at 0w? What's the comparison at, say, 20w or 30w?

OBTW, I run Mystik 10w30.