I responded to a thread on another forum about using 5w-20 in an engine that specs 5w-30. To my knowledge, Ford back-spec'd several of their motors to 5w-20. Again to my knowledge, they specifically stated that the SOHC 4.0 v6 (used in the Explorer and 2001+ Ranger) should continue to use 5w-30. Please follow the attached link and set me straight. http://www.ranger-forums.com/f15/dealer-put-5w20-insted-5w30-113471/
Please Tell Me If I Am Wrong
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5W-20 will serve just fine. Use with confidence! The differences are splitting hairs, even in terms of fuel economy as regards one car. Multiplied over hundreds of thousands or millions of cars, a little equals a lot. But for wear considerations? I think from reading archives, Doc Haas and a few others that ran 5W-20 and turned up flawless UOA that the worries are unfounded. Hey, it isn't as if 5W20 instantly grinds engines to shreds, Ford doesn't need THAT kinda trouble. To me, the SM and GF-4ILSAC additive specs are more indicative of "safety" in older engines owing to the lower zinc and phosphorous content. But the 5W20 v. 5W-30 worries oughtn't be simply over viscosity. But that's just me..
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Technically speaking, Ford does NOT recommend 5W-20 in that engine according to their technical manuals.
A person can run anything they want but if technical competency is to be expected then following the manuals is required.
Do you believe that the OP would get the same responses if he had stated that the dealership had used 10W-30 or 10W-40? I seriously doubt he would. Ford still has a large listing of vehicles that they do not recommended 5W-20 to be used in and I am certain there is a reason. They will take the fuel economy benefit wherever they can get it. This just isn't one of those places.
A person can run anything they want but if technical competency is to be expected then following the manuals is required.
Do you believe that the OP would get the same responses if he had stated that the dealership had used 10W-30 or 10W-40? I seriously doubt he would. Ford still has a large listing of vehicles that they do not recommended 5W-20 to be used in and I am certain there is a reason. They will take the fuel economy benefit wherever they can get it. This just isn't one of those places.
I would use the 5W30 that Ford Specs. I'm a big fan of 20 grade oil, in applications that call for them. Ford said the oil pump used in the 4.0L V6 was not designed for 20 grade oil and is the reason why they did not back spec the engine. I'd pass and stay with the 5W20.
I would say you are correct!I would not use 5w-20 will any confidence at all in that engine based on what the folks that designed and built it say.
If Ford will not risk back specing this engine they 100% have a good reason,if they could they would in a heartbeat to help comply the CAFE requirements.
If Ford will not risk back specing this engine they 100% have a good reason,if they could they would in a heartbeat to help comply the CAFE requirements.
I would say you are right. There MUST be a reason Ford did NOT include the 4.0 in the list of engines that could use 5W-20.
I have the 4.0 V6 in my Aerostar (the pushrod version) - it also is not on the list and I will stay will 5W-30 or occasionally 10W-30.
I have the 4.0 V6 in my Aerostar (the pushrod version) - it also is not on the list and I will stay will 5W-30 or occasionally 10W-30.
5W-20 should not be used in those engines. The issue, according to the people on the Explorer forums, is that the oil pump and plumbing cannot generate enough pressure with the thinner oil.
For later years they redesigned the oil pump to the able to generate the proper pressure with 20 weight oils. You cannot use 5W-20 in those older engines with confidence.
Here is a .pdf that shows what vehicles Ford is back specifying 5W-20 to. Very few were excepted.
However, a 2010 model year Ranger with a 4.0L engine may very well be able to use 5W-20.
Rumple
For later years they redesigned the oil pump to the able to generate the proper pressure with 20 weight oils. You cannot use 5W-20 in those older engines with confidence.
Here is a .pdf that shows what vehicles Ford is back specifying 5W-20 to. Very few were excepted.
However, a 2010 model year Ranger with a 4.0L engine may very well be able to use 5W-20.
Rumple
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AFA back specing:
The engine oil pump typ do not generate enough pressure to compensate for a lower viscosity. The pressure in the bearing is only a couple pounds regardless of the gallery drill pressure. The viscosity/time constant is required to keep the oil in the bearing under shock loading - the oil pump CANNOT do this. And the comment re the difference SAE 20 - 30 is "splitting hairs" is ignorant. Engines are moving to higher specific output and stressors. I hop ethe engineers can make them live for the expected 100+ K.
The engine oil pump typ do not generate enough pressure to compensate for a lower viscosity. The pressure in the bearing is only a couple pounds regardless of the gallery drill pressure. The viscosity/time constant is required to keep the oil in the bearing under shock loading - the oil pump CANNOT do this. And the comment re the difference SAE 20 - 30 is "splitting hairs" is ignorant. Engines are moving to higher specific output and stressors. I hop ethe engineers can make them live for the expected 100+ K.
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