I don't care what the manual calls for. I just did my first oil change on my 2002 F150 5.4 and used Exxon Super flo 10W - 30 as I have used for my vehicles for years.

 

5W30 synthetic makes sense to me for any of the 4.6or 5.4's. In cold climates, I would look into 0W30. I'm conviced Ford recommendation for 5W20 is based on a barely measurable mileage increase, at the unit level, but maybe significant at the total fleet level, and on the Federal fleet mileage certifications.

 

well, my warranty's already run out.....like 2 years ago, so i guess it doesn't really matter for me.

At my work we run Chevy trucks with the 7.4L 454. The owner uses 15W-40 in those. I guess because we use those trucks for extreme service. We tow horse trailers, that can hold up to 12 horses (sometimes we pack 14 in there). So i'm guessing thats about 15K pounds of weight. The oldest truck we have is a '91 Chevy 3500. It still runs hard. I'm not saying use 15W-40, just letting you know that thats what we use in out service trucks.

On my oil cap it also says 5W-20 on it. I'll probably use 5W-30 in it next time i change the oil though. I don't think it really makes a difference. Do what you want.

 

how does the total difference between the Xw number and the -number affect the performance of the oil?

If we want minimum oil flow resistance @ startup and maximum protection @ high temp and load, wouldn't we just be using 0w-90 ?

There has to be a reason why 5w-20 is different @ startup than 5w-30.

 

The "5" in 5w-20 or 5w-30 is exactly the same. When the oil is cold it has the consistancy of a straight 5 weight oil. ( All of this is based on a specific temperature) When the engine and oil reach the next set temperature value, through the miracle of science and chemistry, the oil now has the consistancy of a straight 20 or 30 weight.

 

RODEN,
You make a very interesting point. I started checking around and on the AMSOIL website they said that 5W-20 oil was basically for gas milage purposes. I am going to check around some more and If I do not find anything to the contrary I will change to 5-W30 oil.

 

Forgot to include Chevron to the list of oil manufacturers who sell 5W-20 oil. Who's next? Anybody want to venture a guess?

BTW, in regards to the economy issue, the same thing was said when the engine manufacturers switched to 5W-30 oil from 10W-30 or 10W-40 oil.

All the arguments you're hearing today is the same thing that was said up to about 2 or 3 years ago.

Whenever something is changed, people get upset about it. Sooner or later, the specs are accepted and the controversy starts all over again when the specs change again 2 or 3 years down the road.

 

This is a most-interesting topic, and it looks like everybody has their own opinions about this oil-weight thing. I've been using 5W20 in my 2001 5.4 for 25,000 miles now, and plan on sticking with it. When Ford changed my oil, they used Motorcraft, when I had a L/M dealer change it, they used Kendall, and when I change it myself, I use Valvoline. I can't believe that Ford would put the reputation of their best selling vehicle on the line for nothing but a fractional CAFE increase.

 

Ford engines which are not approved for 5w-20 oil are the 3.9L and the 4.0L SOHC. My source has told me that the lifters in the 4.0L SOHC don't like the lighter weight oil. Don't know why the 3.9L is not approved.

 

My final say on this most entertaining subject.

At my 3000-mile oil change I looked for 5w-20. In a 5 mile radius around my house, and this is in the 5th largest metropolitan area in the U. S. found none, decided it is better to change the oil with what is available than not changing the oil.

At my 6000-mile oil change I looked in the same 5-mile radius, two different Wallmarts many auto parts stores I even stopped at Kmart. Found 3 quarts of Castrol 5w-20 in an Autozone. Not enough so again decided it is better to change the oil with what is available than not changing the oil.

At my 9000-mile oil change well you know what's coming this time again found no 5w-20 anywhere so again changed the oil with what was available.

All I can say is that I'm NOT the only one having trouble finding this product and I'm not out in the "sticks" either. If Ford wants to be a hard @ss about this; can you say "class action Law suite"?

 

Funny, I can't imagine anybody else on this board living in a more isolated area than I am. Hell, to go anywhere from here, you gotta fly or take a boat. If I turn left outside my driveway and drive 200 miles, I end up back at my house! Well, that's a bit of a stretch, but not by much. This has been described as the most isolated place on the earth and it still would be if not for the invention of the boat and aircraft.

If you want to take your vehicles to another dealer than the local ones, you have to ship your vehicle out on a barge (been there, done that, got the t-shirt... never again). The point is, I am able to go to Walmart, Checker, NAPA, an independant place that sells Amsoil, and the Chevron distributor and I can find 5W-20 selling for between $1.75 and $2.20 a quart.

Just called the quick lube joint and even they have 5W-20 oil. Was just quoted, over the phone, $36 for 6 quarts and the filter. Was told that they always ask if you need anything special and that's when you should specify the 5W-20 otherwise they'll put in 5W-30. BTW, the woman who answered the phone knew the F-150 required an "extra quart" of oil over the usual 5 qts. Had a problem looking up their number because it was a Jiffy Lube place, but seems they went independant and I never noticed the change.

 

The bad thing about Jiffy Lube in my area is that they use Pennzoil filters that are just repainted Frams. For two dollars more they'll use an Motorcraft OEM. That tells me that they must have some sweet deal with Fram. I never really had a problem with Frams until I bought my first Overhead cam V8 truck........Frams are garbage.

 

Learned a bit more about oil the other day.

Always knew from running high performance boats that multi-visc oils were a no-no. Engine builders always said to use straight weight oil because it doesn't shear and break down like multi does.

Turns out the oil people put polymers into the oil to make them multi visc. To make 5W-30, they add polymers to 5W oil to make it flow like a 30W oil when hot (212ºF I think high temp standard). Didn't quite understand the process until I realized that the polymers react to temperature in much the same way that proteins do. The only difference is the protein reaction doesn't reverse when the temperature goes down. If anybody is wondering, think -- Egg Whites.

Another thing I learned is that I always thought the numbers meant it protected like a corresponding straight weight oil would. Instead, the numbers only correspond to the FLOW RATE of the corresponding straight weight oils. Nothing to do with protection, just flow rates.

The interesting thing I learned is the wider apart the numbers are, the more polymers they put in which makes the oil that much more susceptible to shear and breakdown. I guess it also means that the more polymers you put in, the more oil you displace.

Now comes the interesting part. Synthetic oils require fewer polymers than dino oil so there's more resistance to shear and breakdown. People always say synthetic is better, but I hardly ever see a good reason why that is. It appears from what I've read thus far, the fewer polymers added, the better and this translates into a better performing oil that doesn't break down as quickly because there's fewer polymers to shear apart in the engine.

So, 5W-20 oil has fewer polymers than 5W-30 does. Fewer polymers has to be better, right?

 

awesome post Dennis.

Could you have links to the stuff you read or isn't it online?

 

I just did a google.com search on multi-viscosity oil and came up with a bunch of hits. Probably looked at 20 or 30 sites, took some notes, and tried to condense it down to something I would understand.

There are a lot more factors involved in making oil, but I always wondered how they did that multi-viscosity thing. I just couldn't figure it out until I compared it to something I understood, proteins. Egg white is mostly protein and when you heat it up, the "stringy" proteins "scrunch-up." That's how it changes from a liquid to a solid.

Next thing I'm going to learn is just what are the "detergents" they put in the oil. At this point, my best guess is it's some kind of solvent. Can't imagine them putting Dawn or Ivory in oil...

Never bothered to learn these things before. Just thought I'd share what a layman learned.

BTW, to be fair... There were some sites that questioned the shear strength of the lighter oils such as 5W-20. For the most part, these sites were independant (such as repair shops mechanics, etc.) and their views were not shared by all. None of the sites that knocked light oils had any studies to back their opinions. So, I pretty much ignored what appeared to be opinions.

The stuff in regards to polymers in dino and synthetic oils was pretty much universal, so that's what I went with.