5.0 coyote 5w-30 vs 5w-20
Beeps and Boops
Joined: Oct 2020
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From: Iowa
Senior Member
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From: Western PA
Wow this thread has come up again....since 2015, I've had my truck stolen 
and replaced it.
With this oil weight debate going across multiple websites, I've decided to perform a test with 5w20, 5w30, and 0w40 oils. I'll be doing a UOA (Used Oil Analysis) with each change, and am going 9100 miles each time.* The oil will be all be from the same manufacturer, with a new filter each change.
This is not about which brand of oil to use, but rather which grade/weight of oil will result in the lowest wear. If the 5w20 is the same as the others, I'll have no problem using it. Right now I believe that a thicker oil will result in less wear, but I'll depend on the test results to correct me if I'm wrong.
Since the Mustang's engine can use up to 5w50, I don't think this will result in any engine damage; plus I've had the 0w40 in for around 6,000 miles with no issues.
I'll post the results here when I am finished ... in around 21,000 miles. Until then let the debate continue....
*9100 miles gives about 10% on the oil monitor, and I have a previous UOA showing my oil can go further.
My thinking is that when the HD pickups were under a heavy load, Ford found that a thicker oil protected better.
and replaced it.With this oil weight debate going across multiple websites, I've decided to perform a test with 5w20, 5w30, and 0w40 oils. I'll be doing a UOA (Used Oil Analysis) with each change, and am going 9100 miles each time.* The oil will be all be from the same manufacturer, with a new filter each change.
This is not about which brand of oil to use, but rather which grade/weight of oil will result in the lowest wear. If the 5w20 is the same as the others, I'll have no problem using it. Right now I believe that a thicker oil will result in less wear, but I'll depend on the test results to correct me if I'm wrong.
Since the Mustang's engine can use up to 5w50, I don't think this will result in any engine damage; plus I've had the 0w40 in for around 6,000 miles with no issues.
I'll post the results here when I am finished ... in around 21,000 miles. Until then let the debate continue....
*9100 miles gives about 10% on the oil monitor, and I have a previous UOA showing my oil can go further.
My thinking is that when the HD pickups were under a heavy load, Ford found that a thicker oil protected better.
Did you ever get your oil analysis completed?
Noticed you haven’t been on here in a bit. Hoping you see it and reply.
Last edited by RubyRedCoyote; May 1, 2023 at 08:52 AM.
Senior Member
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i read that the weight they decided was based mainly on bearing clearance to ensure oil flows fast enough to lubricate everything properly. going too thick can slow the flow of oil to essential parts and cause potential damage.
Senior Member
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From: Timbuk3, MI
lucasjcdr - i read that the weight they decided was based mainly on bearing clearance to ensure oil flows fast enough to lubricate everything properly. going too thick can slow the flow of oil to essential parts and cause potential damage.
.
The bearing clearances and all the other mechanical parts that would care about oil viscosity are absolutely identical between the F150 5.0 which states 5w-20 and the track pack mustang 5.0 which states 5w-50.
5w-30 is not going to hurt anything in these trucks.
5w-30 is not going to hurt anything in these trucks.
Beeps and Boops
Joined: Oct 2020
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From: Iowa
https://www.enginelabs.com/news/what...l-viscosities/
The oil pressure in my 302 drops at hot idle, so I now run 20W-50 in there to keep it above 15psi. It's got a lot of miles on it so I assume bearing clearances are quite worn. It still makes good power and has 180psi compression on all cylinders so I just run it.
The oil pressure in my 302 drops at hot idle, so I now run 20W-50 in there to keep it above 15psi. It's got a lot of miles on it so I assume bearing clearances are quite worn. It still makes good power and has 180psi compression on all cylinders so I just run it.
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Dielectrically 5w30
Joined: Jan 2020
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From: Oregon
No good reasons to increase the first number, the W, potentially worse cold protection.
Keeping the hot idle oil pressure above 15PSI is the important part (done by increasing the second number) and that is right on the edge with a 20 oil, so any worn engine is really going to struggle and should be running a 30 or higher regardless, even if only to give a margin of safety.
Keeping the hot idle oil pressure above 15PSI is the important part (done by increasing the second number) and that is right on the edge with a 20 oil, so any worn engine is really going to struggle and should be running a 30 or higher regardless, even if only to give a margin of safety.
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Anyone else using 30 weight oil instead of the water thin 20? I use mobil 1 5w-30 in my coyote because I'm an experienced mechanic and can't see 20 weight possibly offering the protection of 30. It's been said the only reason manufacturers are recommending 5w-20 and 0w-20 is simply to improve corporate average fuel economy In order to meet government standards. I would say this is true. What's Also intresting is ford recommends 5w-50 in the track pack mustang which has the exact same engine as the GT which calls for 20 weight. I'm just curious what your all thoughts on this are??
Have been using pennzoil platinum synthetic 5w30 and a fram ultra synthetic oil filter since brand new
usually changed both around 8000 miles
engine worked hard by sub zero starts, hauling , stop and go, idling and towing 3000lbs 5 times a week
after about 80k miles it started to use about 1 or 2 quarts per interval
engine now at 200k miles and never had an oil related problem
Personally since i run the truck hard i decided to go with a 30 weight oil at operating temps
but im quite sure as long as you use syntbetic oil, make sure your oil level is correct, use an oil filter with an anti drain back valve you will be ok with 5w20 or 5w30
the fram ultra synthetic filter is one of the best you can buy
