Correct oil weight
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Joined: Feb 2006
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Correct oil weight
Got my F350 6.7 last year I tow a 34 foot trailer about 3 or 4 times a year one dealer did my first oil change and put in motorcraft 15W40 but the dealer I’m using now says I should be using a 5w oil, help please what the hell should this 2018 6.7 be using ?
Laughing Gas
Joined: Feb 2007
Posts: 950
Likes: 6
From: Waco, Texas
Here in Central Texas, I was an avid believer in Motorcraft 15w40 since my 08. And I have had an 08, and 11 and now a 15. But the last oil change, I decided to switch to Shell Rotella T6 5w40. Pulling a 35 ft 5er many times a year, and temps above 100 ambient, it seems to be the better choice. According to my Edge, it runs cooler by about 4 degrees oil wise. On Coolant, it is about 5 degrees cooler when pulling. It does clatter a bit more upon startup, IMO. Fuel mileage, when empty increased slightly and towing, it seems to run quieter and easier once things are up to temp And here this past week, it got down to 20 a couple of mornings and it made things start a whole lot easier than the past. That may be me wishing for better and not worse. But over all, I think the better choice is to use the severe duty schedule and use the 5w40.
Posting Guru
Joined: Aug 2007
Posts: 1,902
Likes: 26
From: BA, OK
The owners manual points out the oil you should be using. 10w30, 5w40, 15w40 all acceptable grades for this engine.
Ford does recommend 5w40 for severe duty which most everyone falls into without knowing it. Idle for more than 10 minutes per hour? Severe Duty. Tow a trailer more than a thousand miles? severe-duty. Extreme heat or cold conditions? severe Duty. Running Biodiesel? Sever duty
I don't know if motorcraft 15w40 is synthetic or not but If you have a synthetic oil change done at a dealer you will pay a premium compared to conventional. Most of us running full synthetic do our own oil changes.
Ford does recommend 5w40 for severe duty which most everyone falls into without knowing it. Idle for more than 10 minutes per hour? Severe Duty. Tow a trailer more than a thousand miles? severe-duty. Extreme heat or cold conditions? severe Duty. Running Biodiesel? Sever duty
I don't know if motorcraft 15w40 is synthetic or not but If you have a synthetic oil change done at a dealer you will pay a premium compared to conventional. Most of us running full synthetic do our own oil changes.
Hotshot
Joined: Jul 2013
Posts: 14,301
Likes: 2,197
there is a min temp restriction with 15w40.....so is great for hot locations but problematic for cold locations.
Post Fiend
Joined: Nov 2001
Posts: 6,748
Likes: 119
From: Tallassee, ALabama
All of the Motorcraft oils EXCEPT 5w40 are NON-SYNTHETIC. I believe they are also not a synthetic blended oil.
https://www.fcsdchemicalsandlubrican...Motor%20Oil%5D
https://www.fcsdchemicalsandlubrican...Motor%20Oil%5D
FTE Legend
Joined: Mar 2017
Posts: 31,962
Likes: 9,194
From: Western NY
All of the Motorcraft oils EXCEPT 5w40 are NON-SYNTHETIC. I believe they are also not a synthetic blended oil.
https://www.fcsdchemicalsandlubrican...Motor%20Oil%5D
https://www.fcsdchemicalsandlubrican...Motor%20Oil%5D
Here in Central Texas, I was an avid believer in Motorcraft 15w40 since my 08. And I have had an 08, and 11 and now a 15. But the last oil change, I decided to switch to Shell Rotella T6 5w40. Pulling a 35 ft 5er many times a year, and temps above 100 ambient, it seems to be the better choice. According to my Edge, it runs cooler by about 4 degrees oil wise. On Coolant, it is about 5 degrees cooler when pulling. It does clatter a bit more upon startup, IMO. Fuel mileage, when empty increased slightly and towing, it seems to run quieter and easier once things are up to temp And here this past week, it got down to 20 a couple of mornings and it made things start a whole lot easier than the past. That may be me wishing for better and not worse. But over all, I think the better choice is to use the severe duty schedule and use the 5w40.
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Posting Guru
Joined: Aug 2007
Posts: 1,902
Likes: 26
From: BA, OK
All of the Motorcraft oils EXCEPT 5w40 are NON-SYNTHETIC. I believe they are also not a synthetic blended oil.
https://www.fcsdchemicalsandlubrican...Motor%20Oil%5D
https://www.fcsdchemicalsandlubrican...Motor%20Oil%5D
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FTE Legend
Joined: Mar 2017
Posts: 31,962
Likes: 9,194
From: Western NY
They also make full synthetic 10w30 and 5w40 as well. I'm not saying this was the brand, but I knew that Triax did. I've seen a lot of semi synthetic brands of 15w40 and 10w30 though.
Last edited by Overkill2; Nov 17, 2019 at 09:14 AM. Reason: Add to post
Hotshot
Joined: Jul 2005
Posts: 13,834
Likes: 26
From: Middle Tn.
The main reason I prefer the synthetic, wether right or wrong, is that you'll have less coking due to the extreme heat encountered cooling the turbo. I used it towing from Ca. to Tn. over 2,000 miles in 100 degree plus crossing the desert with no problems at all. You more than likely won't have a problem either way that you choose to go.
Lead Driver
Joined: Jan 2010
Posts: 6,600
Likes: 84
I ran Motorcraft 15w-40 for 50k miles and have been using Rotella T6 5w-40 since. My simple answer is to run a Ford approved oil from the link above that works for the various ambient temperatures you live/travel in. My opinion is to use an approved full synthetic 5w-40 oil, hook to the trailer any time of the year and drive.
Direct:
https://www.fcsdchemicalsandlubrican...SSM2C171F1.pdf
Direct:
https://www.fcsdchemicalsandlubrican...SSM2C171F1.pdf
Logistics Pro
Joined: Aug 2006
Posts: 4,477
Likes: 4,069
From: Raceland, La.
I've been running 15W-40 Motorcraft since my first oil change. Live in hot and humid South Louisiana and tow a heavy 5th wheel sometimes twice a month. Get it changed at dealer with filter and also a vehicle check up every 5 to 6K miles...$99 bucks plus tax with dealer coupon. Well satisfied with this oil.
Hotshot
Joined: Dec 2005
Posts: 10,256
Likes: 7,693
From: Chino Valley, Arizona
My dealer charged my $89.25 including tax and fees for a synthetic oil change 2 weeks ago.
I looked at the invoice and said "really " I charge $150.00 for an oil change in my shop.
I looked at the invoice and said "really " I charge $150.00 for an oil change in my shop.
Laughing Gas
Joined: Aug 2008
Posts: 832
Likes: 110
You probably got the 10-30 weight. The 5-40 is about $105 more. I cannot avoid bio in most parts of the country. Why any dealer puts 10-30 in is beyond me.