Anyone running something other than 5/30 in the 7.3 Ford gas engine? Warranty and manual police need not reply. I have a large supply of Delvac 5/40 on hand.
5/40 in Ford 7.3 gas?
- Thread starter bshort
- Start date
Use it and don't look back. Once stash runs out - get more of the same, or M1 0W40 Euro.
I would use it without a second thought. Delvac 5w40 is good stuff and SN rated so WAY more than good enough for me.
All day long....
I’m ready to start running D1 or T6 5W40 in my Express LS 6.0 Dexos engine, get that hot oil pressure up!
+1 A great choice imo.
I don't know what these guys are talking about. It's a great oil loaded with detergents but zinc content is supposedly too high for modern cars (i.e. catalytic converter damage). So you wouldn't want to run it in a modern gasoline car unless you have no cats installed (not the case with that 7.3)
If the rig is not burning oil, then the zinc content isn't going to get into the cats to poison them.
Cats fail either way. I'd rather have superior oil and change cats every 100k miles, rather than have mediocre oil and change cats every 120k miles. Rarely do I see factory cats go for much longer than that without the wonderful P0420 code. Aftermarket cats last half of that, at best. Your experience may vary, I'm just sharing mine from last 10 years of owning and/or maintaining roughly ~60 cars between friends and family.
dnewton3
Staff member
I've owned several gas vehicles I've taken past 250k miles, all on the OEM cats. All those engines were fed typical dino PCMOs at the time.
With the 7.3L gas Ford, using an HDEO may or may not be detrimental. It's doubtful it would manifest early in the lifecycle; probably take a long time to happen. But the question really becomes one of the risk/reward issue.
The reward here is that the OP can perhaps use up some stash he's got laying around. Or it's a matter of commonizing oil stock between multiple vehicles?
The risk here is that he may destroy the cats sooner; today's cats are far more expensive as they are more integrated and larger than cats from 25 years ago.
The false economy here is that if anyone thinks the engine will last longer by using HDEO, versus the "savings" of saving the engine from doom by using HDEO in place of PCMO ... well - that's the typical fools errand approach. There's no proof that using HDEO in a PCMO application will make any engine last "longer"; when I say "proof" and "longer", I'm speaking to actual data collected from true controlled study groups and not hyperbole and rhetoric as seen on this site quite often. Engines which don't require HDEOs really don't benefit from HDEOs over good quality PCMOs. These 7.3L gas motors are far too young for any of us to have any proof that they are weak in some manner and "need" a HDEO, but the general success of all gas engines in the common age would indicate you don't benefit from over-indulging in lubes.
Is it worth destroying $1600 worth of cats in the long term to save some money on using the wrong oil in the short term? That's up to him.
He did ask if anyone is actually doing this; using HDEO in place of PCMO with this engine. I'm sure that there are some out there, but none of them have done it long enough for any credible data to have been developed regarding longevity of the engine or the cats in this application.
JHZR2
Staff member
I wouldn’t be concerned. But how you intend to use the engine may be a worthy consideration. Pulling at rated trailer or payload up steep grades is different than going and getting groceries.
Zee09
$200 Site Donor 2023
If Delvac 5/40 meets or exceeds SN, why are some talking about cats?
I've been driving since before the CC first came out. Thinking back I had one fail in 1984, with about 2-3,000 miles on it in a 1984 Ford E-150 I bought new. The failed CC was a factory defect. I stumbled upon that info today, looking back at my Auto Log spread sheet. Since then not one failed, in fact my 88 E-150 still has the original CC. Several of those vehicles were dosed with MMO or TCW3. So I agree with you 100%. Unless the car is burning oil at an alarming rate I wouldn't worry too much about ZDDP killing a CC. JMO
4WD
$50 site donor 2024
Is this the ESP ?
All good points, but I still highly doubt that oil in question (Delvac 5W40 API SN) will kill cats in an engine that is spec'd to run on 5W30 API SN+ Synthetic blends, per owners manual. I'm sure anything API SA-SH will cause an early cat failure in today's sensitive emission systems (and possibly engine failure), but applying that logic to Delvac would be wrong, in my opinion. Is SN different than SN+? Yes, if we split enough hairs looking for a difference. Is it different enough to cause catastrophic issues? Highly unlikely. Based on many UOAs posted on the web from various engine styles and sizes, with different performance levels and lubrication demands - I believe that Delvac 5W40 will prove to be a strong performer in that pushrod 7.3L V8 monster as years go by, as well as any other engine this oil is used in. And OP doesn't have to go out of his way to buy new oil just to meet the spec, he can already save money&time by using what he's got. And what he's got is (in words of Quaker State commercials) "Just D.a.m.n. Good Oil".
4WD
$50 site donor 2024
I ran Delvac 1 5W40 in my 2010 5.3L … and Delvac Super just like Wilson and others here …
dnewton3
Staff member
All valid points. The unknown here is what level of Delvac he has. Older oil in his "stash" may not be a wise choice. However if it's SN or higher, it's kinda moot. He's not worried about warranty, so it's really up to him what the risk/reward ratio will play out to be.
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