The Ford dealer has told me *not* to use 10w30 oil or 5w30 oil in my 03 5.4. They said that the 5.4 since 01 has called for 5w20. The manual and the oil cap are all in agreement about the 5w20.

Aside from the fact that mobil1 5w20 is impossible to find (they stopped making the 0w20 apparently too), does anyone have knowledge about why its so important to stick to the "20" side of the equation on these trucks? I understand that during the winter the 0 or 5 is better than the 10 to make sure oil is flowing at ignition when its zero degrees out (Chicago). But everyone always looks at me funny when I tell them my truck uses 20 weight oil for the summer. And it does sound strange - its not some dinky car, its a 5000 pound truck. If I was towing, would 20 weight *really* provide the lubrication to protect the engine? is 30 or 40 weight going to harm the truck in some way like the 10 could conceivably during winter?

 

The disagreements will start shortly on this btw. I've read and heard from several sources that clearances are tight on most of the modular engines. It also has do with the timing chain and getting the head asap. There's more discussions on this subject every forum you go to. All 20wt oil go through strict testing and most use better base stock and your heavier oils. MC uses a different base for its 5w-20 than 5/10w-30. There's several uoas on bobtheoilguy with good results in many hard working engines. I put 5w-20 Havoline in my 2000 5.4 and it loves it, even my gf noticed a difference in the responsiveness compared to mc 5w-30. Alot of people say that it will cut down the longevity, I don't buy it... frankly if you change oil every 4-5k or 6 months depending on driving habits, it will last as long as the body does. You'll get about 1-2mpg difference with 5w-20 or 5w-30 depending on driving habits. I got the same mpg with M1 5w-30 and havoline 5w-20, but 1mpg less with mc 5w-30. Your decision it what it comes down to. Good luck.

 

As of right now i am running castrol full synthetic 5w20 in my 99 4.6l. I will probably change to 5w30 next change because i live in texas and during the summer it can get pretty hot. But for you, i find no reason at all why you couldnt put 5w20 living in Chicago. I would try both and see if you can tell a difference. Just my opinion.
John
99 f-150 4x4 ext. cab(84k)
rear steel buper..grilleguard w/4 KC lights
tool box..bed linner
dual exaust..K&N air intake...<!-- / message --><!-- / message --><!-- / message --><!-- / message --><!-- / message -->

 

When I bought my new 2001 F-150 4.6, I was hesitant to use 5W20. I was afraid it was a diabolical scheme between Ford and the Feds to (slightly) increase gas mileage at the expense of shorter life. I had been using Mobil 1 in all my vehicles for many years, and they all had run very well for in excess of 150,000 miles. So I changed the Ford factory oil at 1700 miles to Mobil 1 5W30.

When my business tanked about a year later, I began to question the wisdom of spending $5/ qt. on oil when Motorcraft synthetic blend was only $1.42/qt. Many of the people on this forum (and elsewhere on the internet) have been willing to do oil analyses which show very good "wear numbers" using the 5W20 Motorcraft. So I changed to it, and at 98,000 miles, my truck is still running like new. I've also changed to synthetic blends for my other vehicles, with no apparent ill effects.

I believe that eventually, using a heavier weight oil will cause the clearances to open up such that you will use more oil if you ever go back to the "thinner" oil. I realize that the factory may have other agendas than we do, but still don't think we are in a position to make changes to their recommendations. Too big a chance of unintended side effects. I would be especially reluctant to go heavier in an overhead cam engine (but M1 5W30 is actually pretty "thin").

Bottom line: if money's no object, go with the M1; it's extremely good oil. Otherwise, get a good 5W20 that meets the Ford specification (not sure if all 5W20's do...some are just "recommended" for Fords). I don't think you'll notice any difference. And, although it may seem better, I've seen no reason to go to a "heavier" oil in any case (even in hot climates).

 

All 5w-20 oils today will meet Fords spec 930 A which is pretty much a repeat of the 153-H spec. You can find the test criteria in the Oil and Lube forum here at the FTE by doing a search in that forum. The 5w-20 oils are at least a blend of dino and synthetic oils. They must meet a an extremely high standard that you will see in the test criteria. This standard is even higher than most "full" synthetics. The wear metals will be lower using it than if you were to use a common 5w-30. Most often, the wear metals are lower using the blends than the synthetics of a PAO basestock. If you live in a high heat area, it will absorb and release heat faster than a higher viscosity fluid providing for a cooler running engine. Because of the spec standards, it cannot oxidize like any other oil and must stay in its viscosity range. Try that with your over priced synthetic. It will flow with any of the oils except those rated for Artic use which can be critical on an overhead cam engine. The tolerance and clearances in a Triton are the same as the older engines. The difference is in the oil delivery system and ring tension. Your Triton is designed to run on the 5w-20 oils. You trusted Ford enough to buy their truck, trust them enough to use the the oil they recommend.

 

Throwing my $.02 on the table.
Flash knows, I am a die hard 10W30 fan.
My 2000 4.2 has 163,000 miles on it using conventional 10W30.
I view synthetics as a waste of $$ for most drivers (but that is my OPINION).

I bought a 2005 a few months back. After much soul searching, I am now sold on the 5W20 oil for the 2005. (Thanks to Flash)
EVEN IF (and I'm inclined to think it is) mainly about increasing Ford's CAFE numbers, you can't argue with the product that goal has provided for us as consumers.

Having had great UOA results from Havoline 10W30 in the 2000, I have settled on their 5W20 for the 2005.

I used to think I'd wince if I ever poured 5W20 into my truck engine.
I changed my oil last night. I smiled as I poured in 6 qts. of Havoline 5W20.
That's good stuff!
Use it,
and rest easy.

 

my 97 4.6 has been run on 10w40 from the first oil change to 93000 miles, in which i began using 5w30 as specified in the manuel. i have been using 5w30 from than until current (178000 miles) with no problems. the exception is when i used 2w20 for 3 ocis and went back to 5w30 cause i didnt feel comfortable pouring 5w20 into my truck in a hot climate. on either weight oil, it burned no more than a quart between oil changes, which ford states is normal. in a climate like yours i would stick with a good 5w20, synthetic or conv. is totally up to you, i use conv. cause i purchased the truck with 93000miles and didnt see the point in synthetic.

 

well, i finally got back on here to read everything. everyone makes sense to some degree and some of you guys can clearly talk technically way over my head, so i have to just trust that you know what you're talking about.

i've always used conventional oil in my other cars all of which lasted a very long time. this mobil1 every 5000 will be my one expensive experiment with oils. haven't decided what filter to stick with, so for now its been the motorcraft or the mobil depending upon where i'm shopping.

Thanks for the tips. chicago has a very varied climate, you have to be prepared in the winter for below zero morning cold starts (my truck sits outside) and gridlock traffic in 95+ degrees in july...and everything in between. "in the olden days" i just switched oil types seasonally, but i guess with the 5w20 it will go year round fine.

 

i have a 1998 4.6 with 90k and i use 5w30 year round ,couse i see good points about running 5w20 and good points running 10w30 so i stay in the middle and also i use semi-blend oil(mobil 7500)right know.also remmember that this trucks originally came with 5w30 from factory so 5w30 shouldnt hurt any right?

 

Not posting on this thread in any attempt of debating oil brands or synthetics vs dino, just my experience so far.

'04 5.4 purchased new-
Have been a long time user of Mobil 1, intend on staying that way.
At first oil change, I just couldn't bring myself to do the 5W20 thing (isn't that awfully close to sewing machine oil I thought).
Put in 5W30. No change noticed in mpg, noise levels, anything.

Next oil change, winced when I poured in 5W20.
Immediately noticed engine ran quieter, seemed to crank easier, and picked up an average 3/4 to 1 mpg. The mpg increase has remained constant now after yet another oil change.

So I'll be staying with Mobil1, 5W20. So far only place I can find it is Wally World, I really don't like shopping there, but . . . . . . .

Whatever your choice, Don't let it run low & keep it clean.