Bottom line is this...

You may be similar to some of the members posting here, but you are not identical. Just like your truck and engine are similar after 20+ years, not identical.

The oil products you and they use might be identical in the bottle, but as soon as they are in the rotation of the system, they become different.

To be on the safe side, change the oil early and often. The only way to know for sure is to have a UOA accomplished on your oil product of choice after your desired mileage. This will tell you if you are right on the money or wasting money.

Although, if it gives you peace, it is not a waste of anything because time is more valuable than any oil product.

 

And these engines aren't becoming more plentiful and parts aren't getting any more easy to find nor more affordable. Changing the oil is the easiest way to HELP the engine (or anything needing lubrication) live longer. It's no guarantee, but all it takes is watching videos on engine failures due to lack of maintenance (tar coming out of the drain hole) or draining oil that stains the skin to know that there's some negligence going on. Oil is cheap (so far) and if your oil comes out and stains your skin black, you're not changing it enough.

 

To each their own.

Personally in all my vehicles,

I did 3,000 mile changes when running conventional.

Synthetic gets 5,000 mile changes from me. Except the wife’s van which tells you when to change based on driving conditions. I think it’s usually around 6,500.

I do not pay attention to age of oil. But do agree that moisture may be of concern if having crazy temperature variations while sitting outdoors.

Also my personal opinion is that I won’t do a UOA. The money spent could be put towards an oil change. And I have no desire to stretch it out to 10,000 miles regardless of conditions.

Let’s consider the thoughts when purchasing a truck. I wouldn’t flinch to buy one that had changes at 3-5k. But if they told me they were changing at 10k based off of oil analysis then I may pass it up.

Edit: There is a deviation from my madness. This is related to a non-fuel injected vehicle. I now have dad’s 66 F100. It’s cammed up, Holley 4 barrel, and running synthetic oil. I won’t be pushing this to 5k due to the potential fuel dilution. Hard to say what I’ll decide but maybe every 2-3 years depending on mileage. Guessing around 2-3k.

 

x2. My situation is nearly identical to yours on mileage and oil weight (I use the 5-40). But I will say it was a tough sell for me to do the oil change 1x per year at first.

 

Have always gone roughly 6000 miles, 15w40 conventional no matter what. I just changed the oil in my plow truck, close to 3 years and probably 7000 miles. Over that time I probably added a few gallons between what it burns and leaks. Not optimal but is what it is. Always run Motorcraft filters.

 

I actually use my truck like a truck and tow heavy very often with it I do 5000 mile oil changes pretty sure oil is a lot cheaper than a new engine

 

5000mi for me. I use 5w40 t6 year round.

 

"And these engines aren't becoming more plentiful and parts aren't getting any more easy to find nor more affordable. Changing the oil is the easiest way to HELP the engine (or anything needing lubrication) live longer. It's no guarantee, but all it takes is watching videos on engine failures due to lack of maintenance (tar coming out of the drain hole) or draining oil that stains the skin to know that there's some negligence going on. Oil is cheap (so far) and if your oil comes out and stains your skin black, you're not changing it enough."

I have a concern too about slug building up from minimal use. Watched a lot of videos of minimal use of the truck All kinds of products out there but what I've been sold on for decades is Marvel Mystery Oil. Used it with amazing results. I did add a pint or quart in at the oil change. I also bought some Hot Shot stiction eliminator. I sucked out the HPOP reservoir and added new oil with a bit the the HS. Did seem to quit down the injectors.

 

what oil do you use?? I usually go 5K but we tow a fair amount full time RVing..

 

rotella 15w-40