Lower clearanmces in engins the spev. 5-20??

Joined
May 29, 2005
Messages
860
Location
Ozark Mountains
I have been told not to use heavier oils like 10-40, 5-50, or 15-50 in the newer engine's that are supposed to use 5-20 as they have very close clearences and it will damage the engine's because the oil is too thick. Any truth to that?
 
Joined
Dec 5, 2003
Messages
6,990
Location
Everett, Washington
My Taurus engine was back speced for 5w-20. I would not go more than 30wt or 40wt at the most myself. This would only be if oil consumption were an issue.....
 
Joined
Jun 7, 2009
Messages
490
Location
Ohio
What year is your Taurus? I've heard about the the back speced from Ford. Does is cover a 1997 sable?
 
Joined
Jul 3, 2005
Messages
36,240
Location
NY
IIRC Ford back spec'd most of their engines back to 93. There are certain exceptions like the 4.0L which still calls for 5W30. There was a link to all the engines that were back spec'd, but I can't find it for the life of me.
 
Joined
Jun 5, 2009
Messages
965
Location
San Antonio, Texas
In the Ford 4.6's they used to spec 5w-30. Then changed to 5w-20 because they needed better CAFE standing. However, the specs and clearances on the engine didn't change. For this reason i run 5w-30 instead of the 20 the manual recommends.
 
Joined
Jul 3, 2005
Messages
36,240
Location
NY
I tried using 5W20 in a 93 Aerostar that was back spec'd to 5W20 from 5W30, and actually saw oil use drop a little. I'm now running a mix of 5W20 and 5W30 to clean up some left over qts I had laying around. I will run 5W20 again this winter. I was very pleased with the 5W20 oil in the old Aerostar.
 
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