I've run 10W30 since day one.

Was dino at first, switched to M1 at 80K miles.

You can absloutely mix different viscosity oils to arrive at whatever viscosity you want. Folks at this site...
http://theoildrop.server101.com/cgi/ultimatebb.cgi
...do it all the time.
(These folks are a little hardcore when it comes to oil, though. They do lab analysis and other stuff to make sure things are kosher.)

 

The government requires that any brand or weight of oil can be mixed with any other brand or weight. It won't separate or sludge or do any damage.

How can mixing 5w-30 with 10w-30 give you 10w-30? Seems to me that if you mix 1 quart of 10w-30 with 5 quarts of 5W-20 you'd get something around 6W-22.

Yes, you should follow what the manufacturer recommends. But I think 6W-22 (or whatever the mix ends up being) is close enough . . .

 

Take the free oil, go to Wal Mart or a parts store and swap it for what you want. I put 188,000 miles on a '95 T Bird with a 4.6 and never used 5w-20. Only problem was a torque converter and that never saw the oil. Of course I didn't use Quaker State.

 

Rose City Ford, Windsor Ontario. Saw a 2004 Freestar go into the shop with a SERIOUS knock because the old gentleman who owned it decided to use 10w30 instead of the REQUIRED 5w20. I'm just stating what I've learned, been told, and Witnessed. maybe it was a coincidence, I don't know.

 

I find it interesting that so many people here seem to think that they know more about engine lubrication than the engineers at Ford. I doubt that the decision to recommend a different oil viscousity was one that was made at the water cooler in Dearborn one afternoon. I'd bet some big money that Ford's research labs burned-up a lot of engines before they made the recommendation to use 5W20.
I'm playing it safe and only use 5W20 in my $30K+ truck. If you want to gamble, that's up to you. If it were me, I'd take the case of oil and use it in my lawnmower.

MR

 

its all about the CAFE numbers. 5w-30 wont hurt a thing they use 5w-20 to get better gas mileage

 

Damn straight! I paid a lot for my truck also. Using the right oil did me right from the time I got the truck brand new all the way to 39k miles and still going strong. I'm just not taking chances because I can't afford to replace my engine for using the wrong oil. Look guys, if your truck is still under warranty use the right stuff and follow your service schedules.

 

Are they the same engineers who recomended reducing the tire pressure in the tires for the Ford Explorer too improve the harsh ride....need a recap on those events Same engineers who have not yet found a fix for the Injector cackle for the 7.3 PSD....recomended a long lead injector as a fix, NO good. I could go on, but I'll spare everyone the agony.

If Ford burned up an engine using 10-30 or 5-30 under NORMAL conditions I'll buy you a new truck Bottom line....this issue is beat to death in this forum and the Dieselstop forum...No one ever has brought out conclusive PROOF that the oil discused would harm your engine...show me the proof.

 

Not true. If that was the case, why did Ford recommend almost all F150 modular engines switch to 5W-20? Not just the 01's, but all the way down to the 97's. If it was JUST for CAFE, then only the current year vehicles would apply.

The tolerances are tight for the Ford modular engines, and 5W-30 was the thinnest widely available engine oil at the time. Once 5W-20 came out, they began recommending that oil to new 01's and even earlier models as well to help improve lubrication.

Fuel economy was a benefit, but better lubrication for the upper valvetrain and main bearing as someone pointed out earlier was the primary reason.

 

I've used 10w-30 since I bought the truck. It had around 50k on it then. It is a couple hundred miles for 101k now. I've been using Mobile 1. I wouldn't use the oil only because it is Quaker State. My grandfather uses it. All of his engines have developed leaks from the oil.

 

Good grief some people are paranoid.

Disclaimer: If under warranty, your best bet is to run the specified fluid under the specified intervals. Removes any and all wiggle room for dealer warranty interpretation.

That being said:

People here are paranoid about running a 10w30 in an engine that originally specified 5w30, and was changed and back recommended to use 5w20.

I've been running 5w40 oil in my '99 4.6l V8 along with oil analysis. My engine is running AOK a year later, and analysis shows no problems. My posts are over at bobistheoilguy for those who are interested.

As to 10w30 being any thicker than 5w30, under operating conditions there is virtually no difference, as both are 30 weights. The only significant difference is that 5w30 is not as thick at extreme cold temperatures as 10w30. I would be fine running a 10w30 in these motors down to around 0 F, but beyond that would run a 5wXX oil. Under 99% of the operating conditions encountered, 10w30 will be fine.

As to the arguement that why would 5w20 be back recommened, the theories on oiling problems are waaaayyyy off base. I can't fidn the specfic letter at this time, but in order for Ford to be able to count the CAFE credit for specifying 5w20, they had to demonstrate that people actually used the specified weight. This was to be verified by the amount of 5w20 oil sold, as submitted to the EPA by the oil manufactuers. This was to remove the issue of Joe Smoe deciding that despite the 5w20 specification, he was going to use whatever.

Thus, it was in Fords best interest to ensure that a significant volume of 5w20 was sold to demonstrate that it was actually being used. By backwards recommending the oil, they ensured that a much larger audience could use the oil rather than only new vehicles. By doing this, they ensured that the EPA would give them their CAFE credits.

On the arguement of "tighter clearances, etc", do some homework. You'll find the engines didn't change at all around the time of the switch in recommendations from 5w30 to 5w20. There were no internal issues that required the use 5w20 oils.

Furthermore, most people don't realize that 5w30 in particular shears during use. At the end of a long run, it usually ends up as a 20 weight anyways. Thus Ford specifying a 20 weight that was more shear stable isn't exactly a big surprise.

I've run 5w20, 5w30, and 5w40 in my F150. Wear is about the same using all three grades. I've settled back on 5w30 for availibility sake - its just easier to track down, and I have slightly lower oil consumption using it.

If it were me, I'd take the free oil and use it.

 

Nowhere did I mention that engine tolerances became tighter. The tolerances didn't get tighter from 97' - 05'. It's just that a better lubricating oil weight (5W-20) became readily available for use and was shown to improve both fuel economy and engine wear.

5W-30 was the best oil available for the Ford modular engines until 5W-20 made it to the market. Ford is using 5W-20 because it improved fuel economy and valvetrain wear without effecting long term durability, hence their change to 5W-20.

They are recommending it to all F150 engines from 97' to present, including many other older non-F150 Ford engines that originally requested 5W-30. Why would Ford risk long term durability of those older engines by recommending an oil weight that you say only improves fuel when those older engines no longer effect CAFE numbers?

 

I ran 10w30 in my 2004 F-150 with the 5.4 for 5,432 miles and my truck didnt blow up....but it did hurt milege, amd that is a proven fact with heavy grade oils. My truck didnt explode, leak, or shown any sign of a problem when I ran that grade, but I now use 5w-20 because its lighter and my milege went back to normal (13.9 mpg average city)

-Master

**Edit** - Yes Ford recommends 5w-20 because it improves their CAFE #'s.

 

I answered that before. Ford was required to demonstrate to the EPA that consumers would actually use the 5w20 oil. The method of verifying consumer use was to obtain sales records from the major oil manufacturers. Ford back recommended 5w20 in order to open up sales to a larger pool of vehicles, especially when serviced at a dealership. This helped assure Ford that sales would be high enough to claim the CAFE credit on current vehicle sales for its use. It has ZERO to do with claiming CAFE credits on older vehicles.

I'll also note that nowhere have I claimed that 5w20 is risky or causes excessive engine wear. I will note that in my own testing with oil analysis, my lowest wear numbers were obtained using a 5w40 oil in my 4.6l. Of course, this also resulted in a 5% fuel mileage drop relative to using a 5w30 or 5w20 oil (which have statistically simialar fuel mileage according to my 6 years of fuel records and 2 F150's.). 5w20 showed the highest wear numbers in my experience. My records are open for all to see over on Bobistheoilguy. Does that mean that my engine will fall apart on 5w20? NO! It will hold up just fine.

As far as who asked who for a 5w20 oil, the short story is that Ford didn't wait for the manufactuers to produce it, they asked for it and virtually guarenteed a good sized market. 5w20 had been possible in the past - in fact the original Mobil 1 was a 5w20. It took the potential of a large market from Ford who was looking for green capital in CAFE credits to motivate the manufactuers to produce it.

As I recall, the poster asked if there were any reasons not to use 10w30. The short answer is that so long as you aren't operating below zero or care about a very small fuel milage decrease, then go ahead and use it with no fear of causing wear or damage to your engine.

 

I've been changing oil and much more for over 20 years and there is no way to tell the viscosity with out sending a sample to a lab.

And as far as warrenties go. If they can't prove with out a shadow of a doubt that what you used caused the problem. Then it's covered.

Obviously I copied the below information from a buisness site. I edited out the companies name.

Warranties and the Magnuson-Moss Act

You have a customer who is interested in ______ motor oil, but he's concerned that using a synthetic oil or extending his oil drain interval will void his warranty.

Your customer has no need for concern. Congress in 1975 enacted the federal Magnuson-Moss Act to regulate written consumer product warranties. An examination of the law reveals warranties remain intact when ______ Synthetic Lubricants are used.

The law was meant to give consumers detailed information about warranty coverage before they buy.

Congress charged the Federal Trade Commission with creation of the specifics of the law.

The FTC set down three rules under the Act: the Disclosure Rule, the Pre-Sale Availability Rule and the Dispute Resolution Rule.

Those rules require warrantors to title their written warranty as either full or limited, provide a single, clear and easy-to-read document that spells out certain information about coverage and ensure that warranties are available where the products are sold so that consumers can read them before buying.

In passing the Act, Congress meant to give consumers access to warranty information, let consumers comparison shop for warranties, encourage warranty competition and promote timely and complete performance of warranty obligations.

While the Magnuson-Moss Act does not require manufacturers to provide a written warranty, it provides specific rules when one is provided. Among those provisions, FTC regulations state: (c) No warrantor of a consumer product may condition his written or implied warranty of such product on the consumers using, in connection with such product, any article or service (other than article or service provided without charge under the terms of the warranty) which is identified by brand, trade, or corporate name; except that the prohibition of this subsection may be waived by the Commission if ((1)the warrantor satisfies the Commission that the warranted product will function properly only if the article or service so identified is used in connection with the warranted product, and (2) the Commission finds that such a waiver is in the public interest. ((42 U.S.C.2302(C))

The long and the short of it is. If they don't supply it to you for free and they can't prove that your aftermarket part or lube or service schedule caused the problem. Then it's covered.

The company whom I got this from will even litigate the issue if push comes to shove.