i have read other threads but couldn't come up with a real answer for how many miles most of you running synthetic are going between changes.
I went to wallyworld this morning and decided to no longer run the 1540 rotella t in the truck. with 43k miles i decided to switch to full synthetic mobil1 5w40. my plan is to change the oil every 7500 miles, with a filter change in the middle of that. does that sound like it would be ok? if guys are getting longer miles out of the mobil1 then let me know. i used to change the oil every 5k with rotella so getting more than 7500 with synth would be nice.

 

Good for you. Hope you have good luck with it. 7500 is to long an interval. Run this first change for 3k. Change again at another 3k. Then go longer if you wish. My 2 cents.

 

Some people go longer and some people go shorter, but I run 7,500 miles on an oil change with synthetic. I do not change the filter half way through. Ultimately, it is your decision since it is your truck. I get a used oil analysis every oil change.

 

The reason the majority of people change the 6.0's oil at 5,000 miles is not because the oil is dirty or they need a new filter. It is because the 6.0 shears the oil and therefore diminishes the viscosity rating. No amount of filter changes can stop this. The people that have done oa's have found that the viscosty has dropped to the equivelant of 30 weight by 3 to 4,000 miles. That is the reason for the 5,000 mile oil change concensus.

 

Exactly!
And also keep in mind that the 6.0 uses the oil for more than just lubrication. It has a much more important job to do, firing your injectors.
I personally change my oil ( Rotella Synthetic ) between 3-4k miles. Maybe it seems too "quick", but I've been there ( failed HPOP ), and I rather spend the cents more often, than reach in to my pocket for hundreds....

 

Try running it for 5k first, send a sample in to blackstone labs and see what they say about extended use before you try it.

 

Despite the cost of oil and filters, frequent oil changes is one of the best forms of inexpensive preventative maintenance going.

 

I ran good ol' Motorcraft 15W-40 for the first 50,000 miles with perfect oil analysis reports. I changed my oil every 5,000 miles with only a Motorcraft oil filter or Racor (OEM supplier to Motorcraft). The correct filter is more important than any other choice you will make.

I switched to Rotella-Syn due to price (less than Mobil) and for availability at Walmart.

I still change every 5,000 miles due to viscosity shearing (all oil brands and grades shear down).

I use synthetic for the following reasons only (you will note that running nit longer is not one of them):

1) Better cold weather starts.

2) Better protection of the fuel injectors and turbo bearings (both use and are lubricated by the oil).

3) Synthetic has better "high-heat" protection properties.

4) Synthetic oil is a "cleaner oil" due to the extensive refining process... so it is cleaner and less sooty than any dino oil can ever be.

5) I could change my own oil and use synthetic for the price the dealer charges to use dino 15W-40 oil.

6) Changing every 5,000 miles is easier to remember than 7,500 and the 5,000 interval matches up to all other service intervals for tranny, air, diff's, transfer case and other things.

Good luck....

 

i run amsoil and 15k between changes new filter at 7.5k. i have a failed hpop seal (common) at the momnet but the pump is still good. about to install the summit oil relocation assembly and run the amsoil by-pass filter on it and the amsoil modded filter cap for the supply and the other modded oil filler cap for the return.

 

i'll let this first one go 5000 and then see. this is my second powerstroke and the last one i sold with 150k miles and all i ever ran on that one was 1540 rotella. i'm not the kind of person to get an oil analysis at ever oil change. i don't have anything against it. i just trust that the oil is ok and doing it's job and if i change it often enough, why should i worry myself about every little aspect of the oil. i have too many other things to worry about than breaking down exactly what is happening to the oil each and every time. i can see like once or twice a year would be ok to send it in. i never sent a sample in with any vehicle since i've been driving and all have run well over 100k, not just diesels.
if blackstone says 5000 is good, then i'll keep changing it then. and then go to rotella synth for 19 a gallon as opposed to 26 for mobil1. not that 7 bucks is all that much more for peace of mind. my walmart stocks both oils and plenty of others too.
i wish they had fuel filters there but only oil filters.

exactly what do you guys send the oil analysis in with? do they send you a sample container. and do you just grab it as it's coming out of the oilpan when you drain? i have the fumoto valve but never put it in, i don't trust it.

 

this is just my thought but if ford recommends 10w30 motorcraft and recommends changing it every 7500. and the engine is shearing it down to below a 30 weight. if we are putting in 5w40 and it shears it down to 30 after 4k miles, that is still the starting point of where ford is recommending us to use. so even if it's sheared down to 30, it should still be ok to run this oil another 2-3k miles and then change it, especially with synthetic. one of the main factors of running synthetic and paying all that extra money, almost triple the cost if you figure running mobil1, is that you can go more miles. along with all the other things beachbum listed. i can put a lot miles on my truck for work and with a business to run and two young kids, changing my oil less often is a big bonus for me. i have other things to do with my time. when i was single, i had no trouble finding time to change it but now it's just a nuisance. i've heard of big rigs running synthetic oil for over 10k-15k or higher intervals and having zero problems with their engines. 7500 is an odd interval but i don't mind tryign to keep track of it. i just figure out when it;s due next and write it down where i can see it.

 

I switched from dino delvac 15w40 to Rotella synthetic 5w40 for at least the last 3 oil change intervals of 5k. With the Rotella synthetic I would notice the injectors were tapping very loud with ~4k miles on this oil and when draining the rotella the oil would drain like water, so I decided to switch back to good ole Delvac dino and the injectors are much quieter. My truck gets ~19mpg with either oil so I couldn't justify the extra $$, however I do add two quarts of mobil turbo diesel truck with each oil change.

 

i also do an engine flush once a year and i did it before i switched to amsoil.

 

While doing it every oil change isn't as necessary, I do feel like the the $22.50 is well worth it to know what's going on. They will give you a detalied analysis and a personal note as to what the numbers mean. You will be able to discover potential issues before they become big problems. "Just trust that the oil is ok" is fine but wouldn't you rather know that something is wrong before it becomes a bigger problem? They can see if there is any fuel or coolant in your oil. They can see if you have any abnormally high levels of certain metals which can indicate future issues down the road.

As for the sample kit, go to their website blackstone-labs.com and click the Free Test Kit link. Make sure to tell em you heard about them from Ford-Trucks.com. After you get the kit, during your next oil change fill up the small plastic jar during mid drain (while the oil is warm too), put the lid on, put it in a bag, put it in a larger container and put it in the mail. Takes about a couple weeks to get something back via email and they also send a hard copy in the mail. Do a search here on blackstone and you will see the reports that they send. Many people have caught issues that you would never suspect without doing an oil analysis.

 

There is no reason to distrust the fumoto valve - unless perhaps you are rock climbing.

As Riggz stated and IMO - One of the main benefits to UOA is that it will show you fuel dilution from a failed injector(s). That is not something you can "predict" or just get a feel for. Fuel (and coolant) dilution is information you can use to prevent further damage.

As far as metals go ...... I am a curious person and I certainly want to know what they are, but I am still not sure what I would do with the information if I had it. Maybe have the oil pressure / LPOP checked .................