Their site shows these two options for my F-250 6.7L. There is a fairly significant price difference between the two. Both claim to be 100% synthetic. What is the main thing I'm giving up if I go with the Heavy Duty version?
Amsoil Signature Series vs. Heavy Duty
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HD is likely straight group 3 which is also 100% synthetic while ss has some pao but the quantity can depend. You'll be giving up a bit of everything with the HD but not like it would matter. Many engines go north of a half million miles on cheap conventional with very minimal wear and blow by.
Me being me I'd run either delvac extreme or Valvoline heavy duty diesel both in 15w-40 if i wanted something great for a great price. That's much better than the red jug conventional motorcraft diesel these usually get and they still last long enough. Walmart has both ready to ship for free for 22 a jug. Delo XSP is also good and I bought a few gallons a while ago. The Mobil one is available on shelf but the Valvoline one is online only. But if you want Amsoil get either.
Me being me I'd run either delvac extreme or Valvoline heavy duty diesel both in 15w-40 if i wanted something great for a great price. That's much better than the red jug conventional motorcraft diesel these usually get and they still last long enough. Walmart has both ready to ship for free for 22 a jug. Delo XSP is also good and I bought a few gallons a while ago. The Mobil one is available on shelf but the Valvoline one is online only. But if you want Amsoil get either.
Here's a link. Looks like 5W40 or 10W30 are the options. I usually tend to like 5W40 because winter here does get to 0°F or occasionally below, but summer gets above 90°F regularly.
I do NOT intend to go 15k between oil changes.
https://www.amsoil.com/lookup/auto-...ckup/6-7l-8-cyl-engine-code-t-t-diesel-turbo/
I do NOT intend to go 15k between oil changes.
https://www.amsoil.com/lookup/auto-...ckup/6-7l-8-cyl-engine-code-t-t-diesel-turbo/
Off the shelf 5w-40 oils that list the Ford F1 specification:
Rotella T6
Valvoline PBE
https://parts.ford.com/content/dam/...iesel_Motor_Oils_Meeting_Ford_WSSM2c171F1.pdf
Delvac ESP and Delo are not on the list. Funny, I don't see Amsoil on the list.
Ford's required specification.
Well Rotella is trash, so I guess I'd have to stick with the Valvoline PB that I've been running, or the Motorcraft 10W30 that's factory fill and also easily available.
What year truck?
The difference is composition. Base oil and additive package.
How many miles how long in time for your OCI?
Just because T6 has fallen out of favor for hopped up Subarus, lawn mowers, and crotch rockets doesn't mean it isn't perfectly fine for your truck. If it wasn't, Ford wouldn't approve it and plenty of trucks would be dead on the side of the road, including my dad's duramax. It's probably what I would use if I had a 6.7 PSD. (The full syn 15w-40 presently in my 6.7 non-PSD sump happens to be F1 approved.)
VPB is also a perfectly respectable lube. What are we really trying to achieve by switching?
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dnewton3
Staff member
Uh, no. Lets not bash a brand with the widest of paintbrushes.
There are plenty of examples of Rotella doing a fine job. I used conventional 10w-30 Rotella for years in my Dmax and it gave stellar results.
It may not be your favorite, but it's a brand that is respected in many circles.
Imagine for a moment, a brand of oil, someone asks about the difference of two products within this same brand.
Nearly every response is about a different brand completely. And attempting to talk the OP into some brand not even asked about. Because their brand is "better".
Imagine this - With almost NO specifics given about the usage of the oil originally asked about. No oci, no model year, no region, no weather, no duty cycle.
Pretty much my day. Every day.
Well, the OPs signature indicates the model year and weather, so that gets one half way there. Post #3 indicated weather and alluded to OCI. To be clear, I pointed the OP to Ford's list of oils meeting the specification and not to any one, particular brand.
To some extent the manufacturer has already put some thought into which oils are suitable, and indicated a few particular grades and a specification.
I guess I talk out of both sides of my mouth. My cummins truck is currently running four "off label" fluids that do not comply with FCA specification (but approved against other specifications). Motor oil isn't one of them.
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My apologies, for whatever reasons I cannot see signatures on my cell phone. I am on my PC now and see 2019 and see a location as KY. Thanks!
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OK straight forward answer.
They are both synthetic.
https://www.amsoil.com/p/amsoil-sig...-synthetic-max-duty-diesel-oil-deo/?zo=515729
https://www.amsoil.com/p/amsoil-5w-40-heavy-duty-100-synthetic-diesel-oil-ado/?zo=515729
DEO contains more esters and PAO, and uses a bit better additive package, hence the higher cost.
Both exceed the performance requirement of WSS-M2C171-F1.
If you are staying at or below 15K OCI, then either will work just fine. Or you could go 10W-30.
Sorry for my earlier questions, I missed important details on my phone.
OK thanks.
As far as “what are we gaining by switching?” goes, not much. Just convenience, and the *perception* of getting a better oil. I’ve read on this forum a lot of horror stories with Rotella. So I just assumed that since everyone praises Amsoil like it’s liquid gold, and I can order a full oil change kit from them for $120, it seems like a great way to go. Have it shipped to me which prevents me driving all over town trying to source enough oil and a filter, get a better lube, and not spend any additional cash…seems like a winner. That’s why I posed the original question.
As far as my usage, I daily drive the truck unloaded. I tow a 26' camper occasionally. And I see very cold weather in winter but very hot weather in summer. I live in a dusty rural environment. I see gravel roads, 25 MPH one lane roads, 55 MPH highways, and 70 MPH interstates on a weekly basis.
As far as OCI, I follow the on board OLM which always tells me to change prior to 10,000 miles.
As far as “what are we gaining by switching?” goes, not much. Just convenience, and the *perception* of getting a better oil. I’ve read on this forum a lot of horror stories with Rotella. So I just assumed that since everyone praises Amsoil like it’s liquid gold, and I can order a full oil change kit from them for $120, it seems like a great way to go. Have it shipped to me which prevents me driving all over town trying to source enough oil and a filter, get a better lube, and not spend any additional cash…seems like a winner. That’s why I posed the original question.
As far as my usage, I daily drive the truck unloaded. I tow a 26' camper occasionally. And I see very cold weather in winter but very hot weather in summer. I live in a dusty rural environment. I see gravel roads, 25 MPH one lane roads, 55 MPH highways, and 70 MPH interstates on a weekly basis.
As far as OCI, I follow the on board OLM which always tells me to change prior to 10,000 miles.
Rotella was $68 a case this spring from sams with a $40 rebate, and donaldson p502503 is $59 for a three pack from cross filters, so there's your ~$55 14qt full syn oil change. YMMV based on sams club membership and filter choice, but for instance, and for me that would be 100% delivered to my door so no driving around.
I have yet to see a horror story for Rotella involving actual use in a diesel engine as intended. Subaru foamtella anecdotes don't count.
What would really shut the critics (like myself) up is if Amsoil simply submitted for the F1 cert. Or the Cummins cert. Or any cert. Any cert really. "It's good enough because we say so." If Advance Auto's Craquest branded oil and Warren's Mag1 made the F1 list, how hard (or expensive) can it really be? I'll admit I'd never looked at the F1 list prior to this thread. There are some really small-time gas station kiosk last resort oils on there. I had always figured only the big boys could pay to play, but it seems not the case.
If in the end the F1 spec doesn't matter, we could easily boycott Rotella by adding 5w-40 grades of Mobil ESP and Delo 400 XSP back to the list. Remember all that $10 a gallon Advance Auto Delo XSP 5w-40 last fall?
I'll acknowledge that the list I posted was from 2018 and likely...outdated. Maybe Amsoil really is on the 2025 list.
They are not on the list. They don't need to be. Amsoil exceeds the requirement. Truck is no longer under warranty, and that's really not a concern.
So Amsoil's stance is that oils on the list are on the list because they meet (but do not exceed) the requirements? Exceeding the requirements banishes you from the approval list? So why attempt to gain certifications?
Teacher says passing score is 70%. I know I'd get a 95% or more on the test, so the test is now irrelevant. I hypothetically exceed the test because I say so. Testing is a waste of my time. I'm going to recess.
If certifications don't matter beyond warranty then the OP now has freedom to use a host of quality non-approved 5w-40s of his choosing, conveniently available at WM, which has been the conundrum for Ford cert seekers. After all, Amsoil said certs don't matter.
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You've been here since 2015 and you are asking this? Those are silly questions, facetious or disingenuous perhaps. You even imply Amsoil doesn't test.
Amsoil simply knows what the specifications are, tests above and beyond the specs. It's not that difficult to understand.
Certification really doesn't matter before warranty expires, if the oil meets the specifications. Plenty of the threads on this as well.
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