[CptSD]

I change my oil at 5k religiously...I haven't put a lot of miles on the truck lately (as I normally do)I changed it at 60k in MARCH and here we are in JULY and I'm almost to 64k. What I'm wondering is should I just stick to using the mileage as guide to changing the oil or should I use a month restriction too?

Do these Heavy Duty 15/40 Diesel engine oils (I use Rotella T or Delo) loose viscosity over time as well?



Should I do something like 5000 miles or 4 months whatever comes first?? /ubbthreads/images/graemlins/shrug.gif



Thanks,



JB

 

[weasel79]

Even though when you arent driving your truck the oil is constantly breaking down. Thats why manufactures give the option of "miles or months, which ever comes first". I have had some people argue this with the company that I work for but the oil samples have proved it. Its not a fast process but it does break down.

 

[FamilyRide]

I would disagree with "break down". However, it's other things including moisture ad contamination (it sits and doesn't get up to operating temp), that create the need to change the oil per time.

 

[BLEnt]

Also drive alot. Ford says 7.5k is normal with 15w 40. Alot of shell and chevron guys change at 3-5k. what also come into play is how dirty your filter is. 40w will break down to 30w. only oil test will tell how fast your motor does it. Oil break down by heat and also in a diesel by dirt and fuel. If sitting cause breakdown, all the oil on the shelf would have exp. date.

I change at 7-7.5k. I live in southwest, so 15w40 works for me. My filter always looks great, truck run strong, starts quick, and doesn't leak a drop.

Oil is like a women. The choice of brand is up to the man. Stay with mileage and add 12% for over size tires. Clean oil and factory type filter is a must in a 6.0L motor.

 

[weasel79]

[ QUOTE ]
Oil break down by heat and also in a diesel by dirt and fuel. If sitting cause breakdown, all the oil on the shelf would have exp. date.



[/ QUOTE ]

These right here are what makes oil break down. You mix fuel with diesel and you think it stays thick and ok HOW??? Yeah it might not be much but a little bit over time will break it down. The oil on the shelf hasnt even seen an engine yet, how is it going to break down? The mixture of dirt, combustion gases, fuel, very, very fine metal particals, etc. from the normal internal combustion engine will break it down. Why do you think the crank case vents into the intake? For emissions reasons.
Not trying to start anything but just make poeple aware. /ubbthreads/images/graemlins/smile.gif

 

[montanafan]

It doesn't "breakdown", which insinuates a viscosity loss. The additive package of dispersants and detergents does become diluted, and will over a LONG period of time allow some corrosion to occur.
The crankcase will "breathe" a little as outside temps change, so a certain amount of condensation can occur in the engine even though it is not being driven. I don't drive mine much anymore, so I switched to synthetic and only change every 6 months. Less than 4000 miles. I change it in the spring and fall. I doubt if the synthetic is necessary, but it makes me feel good.

 

[montanafan]

The viscosity "breakdown" occurs as it is being driven. The original question was stated because he doesn't drive it much. You are correct about the viscosity breakdown that occurs because of the extremely high pressures that are exerted upon it. Fuel dilution, if it exists, isn't good either, but it doesn't get diluted while it is parked.

 

[jimmy]

When time is used as guide when miles don't accrue, 6 months would not be unreasonable, some mfr's schedules use one year. If the miles accrue slowly because the truck is used for short trips often, short trip being less than 10 miles on a start cycle, then the interval should be less.
If the truck is a tow vehicle and you tow distances with it and drive some other vehicle for daily commutes while it sits, then 6 months or even a little longer would be OK. I would not be worried about 4 k miles and about 4 months. Changing oil too often does not make truck last longer and is not good for the environment unless the environment is the boardroom of an oil company....

 

[CptSD]

Thanks for all the replies guys. I was wondering if any of you have an hour meter on your truck? Or if it is possible to install one? I think this would be a more accurate guage to determine the oil change intervals..Not that I sit and idle a lot but those 3-5 minute periods waiting for the EGT's to come down do add up!

JB

 

[Texrob1]

[ QUOTE ]
Thanks for all the replies guys. I was wondering if any of you have an hour meter on your truck? Or if it is possible to install one? I think this would be a more accurate guage to determine the oil change intervals..Not that I sit and idle a lot but those 3-5 minute periods waiting for the EGT's to come down do add up!

JB

[/ QUOTE ]I have an Hr meter on my 05, Not sure when Ford made it standard Equipment.

 

[CptSD]

I wonder if I can buy one from the Stealership and install it? Do you use the meter to determine your OCI??

 

[jimmy]

Hobbs hour meters are not expensive.
The hourmeter on 05 and up is integrated into the trip computer and is not something you can put in an 03-04.


Ebay auction for one right now is at $11.00 + shipping

go look: item number 280129812436

You wire it into a power supply wire that will be on when engine is running. Fuel pump power supply would be one place to power it up.

 

[FamilyRide]

[ QUOTE ]
It doesn't "breakdown", which insinuates a viscosity loss. The additive package of dispersants and detergents does become diluted, and will over a LONG period of time allow some corrosion to occur.
The crankcase will "breathe" a little as outside temps change, so a certain amount of condensation can occur in the engine even though it is not being driven. I don't drive mine much anymore, so I switched to synthetic and only change every 6 months. Less than 4000 miles. I change it in the spring and fall. I doubt if the synthetic is necessary, but it makes me feel good.

[/ QUOTE ]

Your application is where I think a good synthetic is absolutely right. Primarily for the dry starts after sitting for a while, as well as handling moisture.

For a regular daily driver, it won't hurt at all, but from what I've experienced, it's little to no bang for the buck.