I bought an F350 Lariat CC LB 6.4 in 2009 and have taken meticulous care of it. All maintenance has been done in accordance with maintenance schedule or, in some cases especially oil changes, more frequently.

I haven't had an oil analysis done in several years so on the last oil change I did one to reassure myself. The result is this Blackstone report.

The truck only has 46,900 miles on it and has been used almost exclusively for long distance trips - anywhere from 800 to 12,000 miles about half with no or little load and half towing my small travel trailer. It is used very little in stop and go city driving (only for occasionally hauling construction materials, etc.) and is not a vehicle I'd want to drive in city traffic much anyway.

I've used Ford PM22 in every tank of fuel and I've logged every fill-up and the mileage for every tank of fuel. Overall I've averaged 15 mpg and 14 mpg when towing. I've had zero mechanical problems and not even a flat. My OEM Continental Contitracs were just replaces with BF Goodrich AT KO2s. The Contintentals still had half their tread left but at 8 years old I thought it was time to replace them.

I've been happy with the truck and am happy with the recent lab report. But in some ways a little sad because I just bought a new 6.7 and will be selling the 6.4.

Wish I could justify two trucks.

 

I might consider it if it wasn't upside down. Joking ... I have enough vehicles.

 

looks like indications of fuel dilution. at half the service interval the report shows oil characteristics consistent with 5W40 instead of 15W40. This is why a lot of 6.4 owners have problems...they try to extend oil intervals on an engine with know fuel dilution problems. early oil changes as you have been doing is a must. running the thickest oil possible based on weather conditions is also a must. imagine running 5W40 all year long and then trying to extend that to save a buck. the oil characteristics due to dilution would be horrible.

 

Blackstone doesn't seem to think this particular sample was a fuel dilution problem but a key factor in my decision to get this analysis done was the consistency of the oil on the dipstick. It just "seemed" too thin. It had less than 3,000 miles on it so I took a sample and had it analyzed.

Regardless of the cause for this particular oil being lower in viscosity than it should have been, it didn't seem right so I changed it. I've never seen the point of trying to extend the time/mileage intervals between oil changes. Frequent and early oil changes are cheap insurance.

My trouble free experience with this truck is more than enough to convince me that continuing to monitor the oil and change it more frequently than recommended (especially if something doesn't "seem" right) is the best approach with today's high tech diesels saddled with emissions controls.

I'm more than OK with reducing soot, etc. I just wish the technology was better so that the emissions controls didn't jeopardize the life of the engine. The naturally aspirated diesel in my boat with a dry exhaust blows soot all over everyone in the cockpit when it's not warmed up. But its 35 years old and going strong.

 

You are one lucky man wish that I could say that I too keep my 6.4L in shape but unfortunately I use my for every day use and an occasional hauling here and there. But It's now beginning to show signs trouble ahead. I change my oil and gas as it should be and the oil I use is Amsoil . good luck with your new 6.7 to which I too will changing to soon

 

Yep, some luck and lots of careful attention.

I'm also lucky that this doesn't have to be my daily driver. It would not survive as a daily driver. In urban traffic it gets @ 9 mpg and it would never regen. If I've been driving in town for even a short period I have to take it out for 30 - 40 miles of highway driving.

If I had to use a truck for a daily driver it would be gas unless I was commuting 30-40 miles each way on a highway.