I use Rotella T6 and Ford Motorcraft Filters...

My truck is in tow/haul mode with a camper or camper & trailer about 80% of the time. I just got my first "Change Oil Soon" message since switching to synthetic oil at 10k miles. This oil change lasted 7500 miles according to the trip computer. The oil monitor on these trucks is obviously programmed for non-synthetic oil and I would imagine that Rotella T6 should last longer than 7500 miles but I am no expert. What drain intervals are people using with full synthetic diesel specific oil on the 6.7L? If you are going longer, do you just live with the reminder or do you reset it? Just curious if the dealer will know I ignored it for 3k miles if I push it to 10K on this oil change.

Thanks!

 

I too use synthetic fluids throughout. Engine oil drain interval is ideally based on need. The oil minder the truck came with has all its calculations based on the fluid that is recommended in the manual.
Oil analysis gives you the proper information to determine optimal intervals. On my old six-liter Ford, the sweet spot was about 20,000 miles between oil changes. But I was (and am now) using much better filtration than stock (referring to the oil filters...the old Donaldson air filter on the 6.0L was actually very good at keeping contaminants out of the oil).
If you are using a factory oil filter, drain intervals will be shorter than my 20K figure. But I have not yet determined the sweet spot for the 6.7's.
Except for fuel dilution as being my primary roadblock to extended oil drain intervals, I imagine the drain intervals would be otherwise similar. I have a sample ready to go to the lab with 20K miles on it, so we'll see what they say.
I reset the oil minder each time it goes off. It would be pretty annoying to see the warning all the time if I'm stretching the interval to, say 25K miles! I imagine the dealer has a way to see when the various warnings came on and when they were reset. Hope this helps...

 

Right now I change mine at 10,000 miles. The oil minder starts warning me around 7,300 miles. I put on a bypass filter system at my last oil change. I'll send a sample to Blackstone for testing at 10,000 miles on the oil and see what comes back. If it comes back with too much fuel dilution or other concerns then I will change it right away. If it comes back normal without any concerns, then I will change this interval at 15,000 miles.

I used the bypass filter system on my 6.0 and was always impressed with the clarity of the oil after 15,000 miles and the results of my Blackstone oil reports. The largest interval I went on the 6.0 was 20,000 miles.

 

I keep it simple. I run Rotella T6 and change it when the truck says to.