Oops - wrong oil.
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Mountain Pass
Joined: Apr 2021
Posts: 162
Likes: 159
From: Minnesota
Oops - wrong oil.
So a guy was changing the oil in his 7.3 gas and realized he had put 5w20 instead of 5w30 in the engine at the last oil change 3,000 miles ago. I wouldn’t think this to be too big a deal especially during the winter in northern Minnesota. However, I’ve heard that this engine utilizes a variable pressure oil pump. Hope it wasn’t too bad for the engine. What do guys think? Asking for a friend.
Last edited by Slowthump; Mar 4, 2023 at 03:58 PM. Reason: wrong oil weights
Mountain Pass
Joined: Jan 2023
Posts: 121
Likes: 206
I’m not a fan of those oils except under extreme cold, low load conditions. Many manufacturers who used to say 5w20 have switched back to 5w30.
I think the gentleman who is the topic of this post is fine, however.
Lead Driver
Joined: Jan 2002
Posts: 8,676
Likes: 4,779
From: Itinerant
Good point about 5w20. I wouldn't sweat it either having that oil in it. Just change it out at at your normal interval.
A quick read to give an idea.
https://blog.amsoil.com/5w-20-vs-5w-...he-difference/
A quick read to give an idea.
https://blog.amsoil.com/5w-20-vs-5w-...he-difference/
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Hotshot
Joined: Oct 2015
Posts: 19,710
Likes: 12,848
From: Wyoming
There has been at least one manufacturer that originally called for 5w-20 then switched to a higher viscosity oil when issues came up.
As stated earlier in the thread, during the winter I wouldn't worry too much about it. But I would shorten the oil change interval.
As stated earlier in the thread, during the winter I wouldn't worry too much about it. But I would shorten the oil change interval.
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Fleet Mechanic
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Ford had publications out when they first switched the Modular OHC engines from 5w-30 to 5w-20 for the North American (U.S. and Canada) market. They explained why they made the change (CAFE) and that the 5w-20 still met their standards for use in the Modular OHC engines. The rest of the markets the Modular engines were sold in still specified 5w-30 oil. Ford even changed the engines back to 5w-30 (6.8L, 6.2L, 5.4L, and 4.6L) once they were only fitted in vehicles that didn't need to meet CAFE standards anymore.
The 7.3L though is not a Modular engine and there is no testing at least made public that verifies 5w-20 meets the 7.3L standard. What it is doing or not doing in the 7.3L engine is a wild guess at this point.
The 7.3L though is not a Modular engine and there is no testing at least made public that verifies 5w-20 meets the 7.3L standard. What it is doing or not doing in the 7.3L engine is a wild guess at this point.
Lead Driver
Joined: Jan 2002
Posts: 8,676
Likes: 4,779
From: Itinerant
Ford had publications out when they first switched the Modular OHC engines from 5w-30 to 5w-20 for the North American (U.S. and Canada) market. They explained why they made the change (CAFE) and that the 5w-20 still met their standards for use in the Modular OHC engines. The rest of the markets the Modular engines were sold in still specified 5w-30 oil. Ford even changed the engines back to 5w-30 (6.8L, 6.2L, 5.4L, and 4.6L) once they were only fitted in vehicles that didn't need to meet CAFE standards anymore.
The 7.3L though is not a Modular engine and there is no testing at least made public that verifies 5w-20 meets the 7.3L standard. What it is doing or not doing in the 7.3L engine is a wild guess at this point.
The 7.3L though is not a Modular engine and there is no testing at least made public that verifies 5w-20 meets the 7.3L standard. What it is doing or not doing in the 7.3L engine is a wild guess at this point.
Lead Driver
Joined: Jan 2006
Posts: 7,308
Likes: 250
From: Hartford, WI
You know, that is a coincidence. I have had a "friend" like that. Only difference between us is he does silly things and I don't.
Lead Driver
Joined: Jan 2006
Posts: 7,308
Likes: 250
From: Hartford, WI
Good point about 5w20. I wouldn't sweat it either having that oil in it. Just change it out at at your normal interval.
A quick read to give an idea.
https://blog.amsoil.com/5w-20-vs-5w-...he-difference/
A quick read to give an idea.
https://blog.amsoil.com/5w-20-vs-5w-...he-difference/
Let’s look at 5W-20 vs 5W-30 again. The 5W-20 will remain a little thinner at operating temperature, as indicated by its lower “20” number, while 5W-30 will provide a slightly thicker lubricating film.
Cargo Master
Joined: Nov 2007
Posts: 2,238
Likes: 475
Modern synthetics and blends are are so thin to begin with, the difference between a 5-20 and 5-30 is almost impossible to tell. And with the highly advanced additives packages they perform almost identically, except at the higher temp extremes. Not like old conventional oil when you could see the difference in flow between the 2 and feel a difference in the way an engine ran. If it's that much of concern to you a dump and refill isn't really a huge cost.