I own a F-150 2001 with a 4.6L V8. I recently noticed that it calls for 5W-20 engine oil. However, the past two times I've changed the oil I didn't notice this and used 10W-30 instead. Could this cause problems? If so what? Why does Ford make it where this engine uses 5W-20. This is not an easy oil to find in local stores.

 

I use a semi-synthetic 10W-30. The local dealer said there wouldn't be any issues with that. Not sure about the conventional oil

 

I use Castrol 5w-20. Wal Mart carries it.

 

Check out the Oil and Lubrication forum, lots of good stuff there.

You may find this thread interesting.

http://www.fordtrucks.com/forums/sho...67#post2325067

 

For What Its Worth , Found A Vetern Ford Tech. He Said That Ford

Is Building Tighter Motors, Clearances Are Critical. He Said If I Want

It To Last, Use Only 5-30.

 

that is the biggest mith with the mod motors ford has never changed the bearing clearance in the engines it has to do with the drain down oil passages in the heads is small and the oil pools up and the lower bearings starve for oil and wear out finding 5w20 is easy or just buy it from the dealership for about 2.00 quart

 

I use 5w-30 Moble1 Synthetic. I would ur 5-30 not 10-30.

 

Oil weight is temperature dependent. Unless you live in Canada or Alaska, 10W30 is fine.

The reason the makers have gone to this thin oil is for fuel mileage purposes. If their Corporate Average Fuel Economy (CAFE) goes above a certain point they pay fines. There are lots of little things that add up to achieve their CAFE goal. Thin oil is one of them.

One popular German automaker backed away from 5W30 after learning that engine wear is increased with its use.

Have a great day,
Doc
ASE Master

 

Res.further Finds That Ford Uses Crack Rod Tech. Where Rod Caps Are Snaped Off For Closer Tol. From Fac. Causing Closer Fit, Old Fit Used To Be In Thous.now One Dec. Over Ten Thous. Thats Why You Need To Use 5-30.
Also In Later Trucks Ford Started Using 5-20 In 04/05. I Would Think Long Before Not Using Ford Has Recom. Crank To Rod Bearings Clearances Are Very Vital. Hope I Have Aroused Enought Curiosity So You Will Look Further.

 

Eleanor,

I think you need to do some further research yourself. Cold cracked rod technology for all its positive virtues, has nothing to do with rod bearing clearance. In fact if you go back into the sixties and seventies, minimum rod bearing clearance was even tighter at a range of .0008 to .0028 rather than .0011 to .0027 of the modular V8's of today.

Besides that as long as the oil viscosity is proper for the temperature in which it is used, tight bearing clearances will not prevent a proper oil film. If you are in Canada or Alaska, 5W20 will probably work pretty good. You won't catch me running it in Texas in August however.

Again, the car mfg's are specifying the thin oil as one of the many small mpg improvements that add up to acceptable fuel consumption so that they can meet CAFE requirements and avoid fines.

Have a great day,
Doc
ASE Master

 

guys the line about clearances is nonsense. the 5w20 spec is due to american emissions and cafe requirements, nothing else.

Ford speced 15w50 in the cobra r which is a modular motor, and many of the modulars overseas are speced for 0w40 and 5w50 oil.

Use whatever you like, just use a motorcraft filter.

The mechanic who gave you that line doesn't know a modular from a hole in the ground.

I run 5w30 in my truck because of the increased fuel efficency, but my racecar with a modular gets a cocktail of 10w30 and 15w50 in the hot summer months.

Justin

 

have any of you guys here ever torn down a mod motor i have out of a 2001 ford f-150 with 5.4 he ran 15w40 rotella t since new and the main bearings were starved of oil at 50,000 and were worn out completly the holes in the heads are so small for the oil to drainback down it is critical to use thin oil the overseas engines and race engines have larger drain back holes which allow for the thicker weight.

 

ford389gashog,

Thanks for the first hand information. In what climate was this engine run? You don't have your location in your profile.

Have a great day,
Doc

 

i live in southeast louisiana, and my 97 (purchased used at 155,00) had 10w40 ran thruogh it until i bought it. it now has 172,000 and dosent burn a drop of the 5w30 i currantly run nor does it smoke.

 

Thanks Doc,i'm Always Trying To Learn As Much As I Can. Please Excuse
Rookie Mistake. I Live In Lexington N.c. Average Temp. About63 Year Round
Except Jan/feb. 10/30 Alright Except Milage? Thanks Again.