Originally Posted By: dave1251
Alright my biggest complaint is that CAFE=less engine protection. You are correct the motors were not revised and clearances were not changed to use 5W20's like I stated 20 grade oils have been used for many years.
"And if a car or truck is designed and needs a specific oil weight does i make sense to simply substitute that oil with another weight because it's not prevalent in that area? No."
Well I do not know a single motor that has to run on a specific viscosity or it will explode. Oil is dynamic as the temperatures in your engine changes so does the viscosity. If you have seen my arguments with posters that state you have to use 0W-40 synthetic because the motor has a European car model symbol on it, I will make suggestions on what the poster has in his/her area and will match a substitute that although is not ideal match to a 0W-40 oil I will show them the data on what has similar HTHS performance that the engine required while under warranty, with the caveat the cold flowing performance will be compromised. So often you use what you can obtain. I do not imagine 5W20 is readily available in the areas that you mentioned that different grades of oil are recommended for Ford vehicles. Just because a country is a 1st world nation does not mean the country has the access to resources that us in the U.S. and because of being our neighbors Canada has. Now imagine a Mustang being sold in a county that is not particularly wealthy what do you believe will be recommended to used there. So the whole 5W20 is not recommended in Timbuktu does not have too much merit also because often 5W20 is not readily available.
I agree with almost all of what you said. I think my goal as many of the other members who own 5.4l 3v want to know simply what is the absolute best oil viscosity for the engines longevity. This question may never be answered.
From what I have read, heard and seen, I don't believe Ford changed to 5w20 so it could extend the life of the modular motors to the absolute maximum limits. I don't believe they have any monetary or other interest in doing this. The mpg savings on the 5w20 are miniscule as it relates to each person but of course more substantial when you talk about the fleet of 5.4s currently driving. I feel simple the CAFE and emissions reduction was their sole motivating factor behind the 5w20 change.
Again, will the 5w20 take the 04' and newer 5.4l motors to the 150K, 200K, 250K mile mark and beyond? I am not sure. Just from the thousands of posts I have read, I have seen many more 200K+ mile vehicles mentioned that were serviced with 10w30 or 5w30 than I have seen with 5w20. I don't recall any that have made it past the 175K mark that have been serviced with 5w20. Again, that means next to nothing to anyone else and is of course no proof at all that 5w20 is any less capable of maintaining a motor to great lengths, but it does make me wonder.
