5w20 winter and 10w30 summer??

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1,381
Location
Southeast Kentucky
Once my Ranger falls out of warranty later this year, I am considering using Motorcraft 5w20 in winter due to its very good cold weather property, and then switching to Motorcaft 10w30 for warmer weather. Will this difference in viscosites have any negative effect on the engine?
 
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413
Location
Marietta, GA
quote:
Originally posted by mikemc: I am considering using Motorcraft 5w20 in winter due to its very good cold weather property, and then switching to Motorcaft 10w30 for warmer weather. Will this difference in viscosites have any negative effect on the engine?
That sounds reasonable based on ambient temperature. I do not think it would harm the engine. I would not go any thicker than 10w-30. I am going to run Castrol GTX 10w-30 (first OCI)in an 04 Odyssey and the Motorcraft (Conoco) 5w-20 in the winter. Remember, most of the 5w-20s are blends. Is the Motorcraft 10w-30 a blend or plain dino? If it's plain dino, I would strongly recommend a blend like Schaeffer 7000 10w-30 or a full synthetic like Mobil 1 10w-30 or Amsoil xw-30.
 

mikemc

Thread starter
Messages
1,381
Location
Southeast Kentucky
quote:
Originally posted by Schmoe: I'd use a 5W-30 year round. Let's not get into the "thicker is better" routine [Big Grin]
My reasoning is that MC 5w20 and a good dino 10w30 appear to be pretty shear stable oils. Then again, I've been using dino 5w30 for over 15 years without anything blowing up. [Roll Eyes]
 
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2,533
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Pittsburgh, PA
[Cool] If it is a late-model 4 cyl or 3.0 Ranger you can use 5w-20. If it is a 4.0, that oil is a no-no. [No no] I don't have the link handy here at work, but at www.thedieselstop.com they had a list of vehicles and engines that Ford approves for 5w-20. I've posted it here before. If you want something else for winter then look at 0w-30. I just posted a UOA with that in my 4.0.
 
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