Powerstroke 7.3 - Rotella 5-40, 15-40 or Delvac ?

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Apr 12, 2009
Hello everyone –
First post here. I have been lurking for a long time and decided to join so I can search and have some good input about my oil ideas. Here’s my deal – I own a 2000 7.3 Ford Powerstroke truck and have had it for about 8 months. First oil change was Rotella 15-40, and the truck liked it, except it was a little harder to start in the winter. I live in western WA so ‘cold’ and ‘winter’ are relative terms. I switched to Rotella 5-40 and it was much easier to start in the cold, and it again, truck liked it. I have run this oil for over 5,000 miles and intend to get an oil analysis done with this change. From what I understand, this is the farthest I should stretch my changes because of the breakdown of the anti-foaming additive which is crucial for the Powestrokes. Will the anti-foaming agent number be included in a standard blackstone?

Next question is this – am I wasting my money using the 5-40 vs the 15-40? I can get 15-40 rotella for 10.50 a gallon, and the rotella synthetic is 19.00 a gallon… and I just read that I can get 3 bucks back a gallon on delvac 15-40, so it may even be cheaper to get it instead. It takes 15 qts to change the oil and with me needing to do it at 5000 mi intervals max, perhaps I really should consider going with the standard stuff and changing between 3-4000 miles? Maybe I should do the ‘winter’ change with 5-40 and the summer changes with the 15-40? This is where I am really looking for some input. What do you all think? Who has ‘strokes and has had good analysis results with what?

Thanks everyone!
I am a self-employed diesel mechanic and a proud owner of a 1997 f-250 hd with the factory 210hp 7.3l tdi psd. I am currently running a 3.5 inch down pipe and a 4 inch to the six inch stack, a TS-Performence 6 position flip chip; which give 50, 75, 100, and extreme hp setting plus stock and high idle. I have been running m1 tdt 5w-40 7,500 mile no problem, and I run 15w-40 5,000 miles or 200 hours if i dont put miles on her. International version of the motor is rated to do 6 month, 10000 miles or 350 hours on blain oil delvac 1300 15w-40.
Good to know! I have been worried about the foaming additive breaking down before the extended intervals. Mine has a small surge/miss at idle and some on other forums are saying that it could be from the foam additive breakdown. Hmm, now to decide what oil to buy for the next change...

The HEUI systems like a thinner grade oil, especially in winter, for easy starting. While HEUI tends to shear down a 15w-40 oil, it won't much shear a 10w-30 HDEO. It's almost as though they simply prefer a 30 grade. The 6.0L PSD are the same way; perhaps even more so.

But as far as protection performance goes, any decent brand name will suffice for moderate OCIs.
Thanks for the input! I ended up buying 8 gallons of delvac 1300 super 15w-40 for 11 bucks a gallon at walmart today. I couldn't pass up a deal like that with the $3 rebate. Two oil changes for less than the cost of one rotella 5w-40 synthetic change, can't really go wrong there. I have heard good things about the oil, and I have been using 5w-40 delvac 1 in my VW TDI beetle with good results for years. I have heard that many prefer the devlac to the 15w-40 rotella, because of better anti-foaming capability. Who knows if this is [censored] or not, I have never seen facts about it. Any input?

Scott: Last winter I switched from Delo 15W-40 to Delvac 1300 15W-40. Now I know from UOA that Delo is one of the best Dino HDD oils. My 7.3L just didn't like this thick oil during the winter months. In my part of the country Delo 5W-40 is no where to be found... Both the Delo 15-40 and Delvac 15W-40 contain moly, which I feel is a major roll player in oil. Anyway-->With my summer oil change I use 3gals of Delvac 15W-40 and 3qts of M1 TDT 5W-40 {Mix},with an Amsoil oil filter. My 7.3L really seems to approve of this mix. The real difference is in the winter mix--> 2gals 15-40 & 1gal+3qts M1 5W-40. {Fast Startups}-{Very little romping}-{7.3L is so much quieter and smoother idle}.

I agree the $3 rebate is super. I don't buy all my oil at once, I normally buy 1 gal every other trip to WM or AZ.

I do think the Rotella foaming problem was corrected by shell along time ago. Rotella is a good oil, I just think Mobil has a better base oil & additive package then Rotella. {Mainly Moly}.
I also add with every summer oil change--Schaeffers Moly E.P.[2pts}.
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