5w20 Motorcraft or 5w30 Pennzoil Synthetic

[crazyoildude]

I have a commercial account that we rebuild engines for and one of the master tech's that had worked for ford until he retired about 3 years ago says he recommends using 5w30 pennzoil or valvoline synthetic over the 5w20 Motorcraft on all the 4.6 modular v8 engines in the summer i said we use 5w20 motorcraft all year and he says absolutely 5w30 synthetic is a much better choice... Some of his cars mostly Mercury Grand Marquis and many ford trucks we rebuild have over 250,000+ miles on them (they are a very large limo and taxi company..
What does everyone think?

 

[panthermike]

5w20 is proven in these apps, but 5w30 won't hurt a thing either.

My mechanic services many Towncar's with high miles, some over 300,000. He really believes in thicker oil in the summer. Anyways, being in Phoenix, he gives these cars 20w50 year round! I wouldn't personally do that, but the miles don't lie, plus the climate isn't cold.

Sometimes I think oil weight is overthought here; unless the engine has VCT or something.

 

[buster]

He doesn't know what he is talking about.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1666049&page=2

Quote:
Q. Does the difference in price between Motorcraft® SAE 5W-20 and SAE 5W-30 really reflect a better oil?

A: Yes, Motorcraft® SAE 5W-20 is a better oil than Motorcraft® SAE 5W-30. However, in response to Dealer Council Ford Motor Company has priced Motorcraft® SAE 5W-20 Premium Synthetic Blend Motor Oil exactly the same as Motorcraft® SAE 5W-30 Super Premium Motor Oil if you purchase it in BULK, 55-GALLON DRUMS, or the 5-QUART JUG. Only individual quart bottles of Motorcraft® SAE 5W-20 cost more than Motorcraft® SAE 5W-30. Again, the better base oils, and increased additives such as friction modifiers and anti-oxidants used to formulate for the performance levels in the SAE 5W-20 do cost more, and reflect the significant increase in performance.

 

[modularv8]

The newer modulars ( 2004 +) have high volume oil pumps, 75 psi @ 2000 rpms at operating temperature. Also, the cam and VCT have oil ports designed for the 20 wt oils.

But it is his equipment, let him run whatever he wants. Even though there wouldn't be a catastrophic failure with 5w30, it is hard to say which weight is optimal for durability.

I've read some papers regarding Ford modulars and they really are designed to operate best on 5w20. (seals (thicker oils create more heat as they shear causing seals to crack), ring wear (film thickness), cylinder lubrication system (mist), timing chain lubrication (oil port fed), etc.)

 

[4ever4d]

I do like PP have not used PU yet but Motorcraft 5-20 is designed and recommended by Ford for Ford engines so i can't see how Pennz. would be any better.

 

[CROWNVIC4LIFE]

Originally Posted By: crazyoildude
I have a commercial account that we rebuild engines for and one of the master tech's that had worked for ford until he retired about 3 years ago says he recommends using 5w30 pennzoil or valvoline synthetic over the 5w20 Motorcraft on all the 4.6 modular v8 engines in the summer i said we use 5w20 motorcraft all year and he says absolutely 5w30 synthetic is a much better choice... Some of his cars mostly Mercury Grand Marquis and many ford trucks we rebuild have over 250,000+ miles on them (they are a very large limo and taxi company..
What does everyone think?


As I recall you mentioned awhile back the Jersey State Police run 5w20 Motorcraft [blend I believe] in their 4.6 engines with no issues whatsoever...The police departments that do not have a service center down here in the jungle let Ford do the oil changes and they are using 5w20 Motorcraft Full Synthetic in their 4.6 engines with no issues whatsoever...I would say stick to the Motorcraft for sure.

The 4.6 Ford engines seem to love 5w20 Motorcraft.

 

[Ben99GT]

Modular Ford V8s love a lot of oils...

 

[crazyoildude]

i always tell people that the 5w20 is the oil of choice for those engines... But someone that has worked for ford and was actually involved in some of the testing does not agree with me..I just was curious what everyone else thinks.. He says the 5w30 shows much less wear (in the lab i assume)
So if that is true those of us using the 5w20 (i use it) will get less mileage out of our engines so i guess i should be prepared to rebuild my 4.6 at around the 350,000 mile mark..