Just wondering what everyone recommends motor oil wise for the 7.3. I didn't get a manual with my truck so am not sure what the book says to use, or how much to grab. A few friends use delo 400 but others says that is a high detergent oil and to stay away. So anyway I did a quick search but didn't come up with much. Thanks!

 

15-16 quarts (4 gallons), and your favorite flavor of 15W-40, or 5W-40 if you want to go syn. Syn is a bit more expensive, but is way better at start-up, especially in cold areas, and you can run it longer. Book says 5000 mile oil change intervals, I run about 7500 or so on Rotella syn. You can get Rotella and a Motorcraft FL1995 at WM. Dino is about $12/gal, Syn is about $19/gal. Filter is $10.

EDIT: If you do the math, you spend ~50% more, and you can go 50% or more further on the syn. It works out.

 

I agree with Joe.. Shell Roletta 5w40 is the way to go.. Get it at Walmart..

 

Well my truck had been running with amsoil 15w-40HD synth for at least the last 6yrs at least.Previous owners records. Last month after an oil analysis i had almost 5% diesel fuel in the oil. I did all the o-rings on the injectors about 3 weeks ago and switched to Rotella 5w-40 synth oil and i did notice a difference on ease of start-up and just an overall quieter injector noise. It sarted up with less noise and even down the freeway there is less noise. Plus Rotella was alot cheaper. I am sold on it.

 

The HEUI Injection system in the 7.3L is tough on oil - Injector Control Pressure can easily hit 3,000+ psi which will shear the viscosity over time. So chose a good CI4+ or CJ-4 rated diesel oil(found on the back of the container). As far as 5W-40 or 15W-40 is concerned, both will work well in the 7.3L. Many choose a 5W-40 for better cold/winter starting characteristics. Also, a full synthetic diesel oil will be a 5W-40 and not a 15W-40.

Delo 400 15W-40 is a very good oil and has shown very good results on Used Oil Analysis Reports for the 7.3L. Easily run 5-7K miles in most applications.

Shell rotella 15W-40 works good but will start to shear down to a 30 weight around 4-5K miles depending on mods & towing. So, just keep the OCI around that mark.

Rotella 5W-40 synthetic also shows very good results on UOA reports and can easily be run 7K miles.

I run Schaeffer's Series 7000 15W-40 Syn blend - have had my best UOA results with it. 8-11K Oil Change Intervals.

Schaeffer's Series 9000 5W-40 is also used by many on this forum with very good results.

Rotella just came out with a syn blend (T-5) 10W-40. Haven't seen any UOA results for a 7.3L yet, but it looks like a good product.

Here is a copy of my last UOA report - been running this brand now for 80K miles.

 

i run rotella 15-40 and a quart of lucas i run mine 5000-7000 miles or so depending on how i have used the truck. some say not to run lucas but ive always run lucas in everything and will continue to run it till it messes something up.

 

i wish i could run schieffers but it's too damn hard to get when i can just got to the wal-mart and get some rotella

 

Lucas is nothing but a viscosity improver. Add a quart to your oil and all you are gonna do is make it a foamy 50 weight oil in a PSD. Here is a Used Oil Analysis of a virgin sample of the stuff. Nothing much in the additives - just increases viscosity. The CST viscosity of Shell Rotella 15W-40 is in the 14-15 range, this stuff is 124..

 

They can ship it to your house via UPS or you can call the 1-800 # and see if there is a sales rep close to you in TN. The website only shows the retail locations not the sales reps. A sales rep can save you 10-20%. Just a couple of options if you wanted to give it a run down the road. Send me a PM if you need help finding a Sales Rep.

 

FYI, Walmart sells most oil in 5-quart containers, not 4-quart. Just a little FYI.

 

I buy Delo 400LE 15W40 in one gallon (4 quart) jugs at Walmart for $10.50 each. At Costco you can get the aforementioned oil in a 3-pack for ~$26.

I don't recall seeing diesel oil in 5 quart jugs at Walmart, but almost all of the regular motor oils are in 5 quart jugs.

 

The only diesel oil in 5 quart jugs I've seen is Motorcraft 15w-40. Everything else is in gallon jugs. Even Super Tech. LOL

 

Well I went with the Motorcraft diesel formulated 10w40 and a motorcraft filter. Figured the truck has had nothing but motorcraft parts and oil its whole life, might as well keep with it. I did not see that mentioned anywhere on this thread...does anyone have any opinions on the Motorcraft oil?

 

10W-40 isn't diesel rated oil. You sure it isn't 15W-40?

 

Your right, it was 15w40 "Powerstroke Diesel" Motorcraft oil.