I know this has probably been beat to death on here, but since Im new to the 6.0L Im going to ask anyways. I have the nice excel spreadsheets with all the good info and it suggests 5w-40. Owners says 15w-40. Im in Oklahoma running in the 40-70s right now, winters sometimes get to 15-20. Summers like last year 113F. With all that being said what weight is suggested to run. In my 7.3 I ran 15w-40 Mystic synth blend year round no issues, but i knwo the injectors in the 6.0L are set up a little different.

Just ordered coolant filter kit today.

 

im in alabama an im runnin 5w-40 rotella in my 6.0L with no issues.temps here r similar to where you are.

i would also suggest that u get a scangauge for your truck , so you can monitor vital engine reading. like coolant temp , oil temp , FICM voltage an many others.

 

Its on my wish list to get one. Ford had just worked on the motor before I bought it. They replaced the head gaskets, egr, egr cooler, head bolts (too bad not studs), injector orings and a few other items that say "Kit" on the invoice I have but not sure what they were.

 

Just my 2 cents ...

I would love to do 5w-40 of the best oil in the world every 3,000 miles.
If I had Romney money I probably would.

I have 2 diesels that do high mileage and the 5,000 mile intervals come quick and fast, esp in the summer when I do most of my mileage.

My 2003 6.0L with 243,000 miles has all original injectors. Until this year I always ran 15w-40. This winter I started doing 5w-40 and 2 oil changes (5,000 miles apart) got me through the cold months. Now I'm back to 15w-40 for the warmer months ... mostly because of my finances. I also do plug her in over night when the temps drop.

I do shop for deals when I buy my oil and availability is important too. My first 5w-40 was T6 that I got for $23 at an Autozone. When I went to get 5w for my second winter change I searched high and low and could not find T6 for less than $28 per jug, and even then there were only 1 jug on the shelf. My local NAPA had 5w-40 valvoline for $21 per jug ... so guess what, that's what's in her now along with some of the left over from the previous T6.

Also, because I'm usually buying 4 jugs of 1 gallon for each change, I'm usually left with 2-3 quarts extra. So in my garage I have bottles of Amzoil, Rotella, T6, Valvoline, Mobil Delvac and I do mix them.

To me most important is having the right OEM oil filter cap, and using the correct OEM filter. I do let my changes slip sometimes as time and other commitments jump in front of me, but rarely do I go past 8,000 miles. Usual is 5-6K.

That's engine oil 101 ... or not even. You can find discussions on the web with oil scientists and industry experts examining each brand for various compounds and additives. Even amongst those guys you'll find some disagreement ...so after my attempts to absorb some of that industry talk I still end up back at line 1 above.

Your mileage might vary ... mine is 17mpg

Alright maybe there's 3 cents in there ...

 

I use 5w40 synthetic, but I get it cheap through work. Otherwise I would probably be in the same boat. I did however get a notice from Ford in the mail that stated 15W40 is not adviseable. The dealers up here in Alberta are putting in 10W30.

 

That's interesting. Did they give a reason why? Is it the lower temps you guys typically see up there?


I have been considering that as an option. I like the prices I've seen for synthetic 10w-30 ... not a huge leap up from the dino 15w-40 but not as steep as the 5w-40.

 

Im kinda in that same boat, Id love to run full synthetic but its pricey. I'll probably do like your doing and run one during the summer cheaper 15w-40 then if its going to be cold enough switch for those few months. This winter has been very mild. It currently has the wix oil filter so I bought a new OEM oil cap so i can go back to factory filters.

 

Best thing you could have done for your truck

Reps sent for that, I've been in rep jail for a while so I gotta be a rep wh*re for a while

 

dieselfiltersonline.com will be the cheapest place to get the OEM filters. I'm sure you've seen that already, but sending it just in case. Great prices on filters.

 

That site is on the top of my favorites list. I typically order in higher qtys to save on the shipping.

 

15w40 motrocraft for me year round. Im in texas. it only gets hotter here not colder.

 

I think that's going to be my best bet plus saves money

 

ya in OK you have the same thing we do here. the only tip I have is change your oil often. mine is done between 3-5k closer to 5k now that im driving on the highway all the time

 

I think the temps are the factor here I am in Mass and run 5W40, where you are 15W40 would be the choice.

 

Up here in Canada, we are not able to run 15w40 in winter. Cold is -45 C which is about -40 F. We must run 10w30 or synthetic 5w40 in winter I am running 5w40 syn year round, cause the shoulder seasons it's really to cold to crank her up with 15w40 in it. There is a cost to this in terms of oil change costs. I am changing at 7500 km or 5000 miles on the button. My truck has all original except batteries, tires, shocks, windshields, just over 100k miles. I think the synthetic is really a lot better on cold starts, cold weather, and still provides all the towing protection at any temperature.