Originally Posted by oil_film_movies
Originally Posted by audi_guy
Originally Posted by zeng
... despite 'severe' viscosity shearing and fuel dilution
Not to be an a$$ about it but how do you know it severely sheared?
It's still in grade. Since the search engine here limits the search to 5 prior years, I don't see a VOA of MC 5w30 that would give the Viscosity at that time. Unless there is a
VOA available, shear amount cannot be characterized.
And I still don't buy the fuel dilution as being an issue here unless the lab is incorrect in their reading. The wear numbers just don't show that to be an issue.
Not still in grade; it became a 5w20 at 8.7 cSt. I wouldn't say it is severe, just some viscosity loss due to shearing and fuel dilution together. Oxidation pushes visc up, so its a little worse than it may appear at first.
That was not many miles, meaning visc loss is concerning, just not a big problem if you change the oil in 5k miles all the time, or simply put in a thicker HTHS oil to start with and go the full 7500 miles......
We know what new MC 5w30 is:
https://www.fcsdchemicalsandlubrica...a%20Sheet%205W30%20Synthetic%20Blend.pdf and its kv100=10.8, typical for a 30 weight.
Sorry Tiger but you are causing alarm over nothing. Ford beat the snot out of this design with nothing but off of the shelf 5W30 motorcraft. There is nothing to be gained by increasing viscosity other than a feeling to control an varible.