OIC on summer only tow unit ...

[JCHJ]

Folks-

I use my 1997 4 door, one ton 4WD 7.3L PS to pull a summer use 24’ toy hauler. I bought this truck with three miles on the odometer (now at 153k). She has been overly maintained/babied (fluids, filters, oil, gear lube, grease, etc.). I currently use Rotella T6 5-40 and in the past, my OCI was 5-7k. The truck started its life on Rotella Dino 15-40 (at 3k OCI’s) but with Montana winters she struggled, hence the 5-40. The truck runs well on 5-40 and does not/never has used a drop of oil (no leaks).

My concern, hence this post, is I now put about 3-500 miles per summer on her, what should my OIC be? Will this oil time out? Am I making a mistake leaving low-mile oil the crankcase for multiple years?

The truck pulls/brakes a fairly heavy load up and down a demanding Wyoming grade once a year with the trailer. Am I wrong not to do a yearly oil change at 500 miles? It seems a bit overkill? I am now thinking 3k? My Shell jobber laughs and says I am his best customer ...

Admittedly I anticipate the answer here will be to do an OA and see. And that I should. I am new here, and will continue to scour the site for related posts/information.

I had a bit of down time and pause over the Holiday and thought I’d ask those in the know…

Thoughts?

Much appreciated.

 

[Creekside]

I vote that the interval be 2-3 years. I think I've read here that synthetic copes better with what little condensation might show up over winters and periods of rest. I would recommend a chassis lube and fluid check every year though. That gives you the best opportunity to spot things before they leave you on the side of the road.

 

[zrxkawboy]

Yes, a UOA would be a good idea. Otherwise, I personally would change the oil every other year and not worry about it.

 

[Bighorn2500]

Does it sit the other 7-8 months stored away or does it get a run long enough to get up to temperature in the off months?

I would think the TBN would still be fine for 2-3 years for only a couple hundred miles and little to no moisture would have accumulated. UOA would provide you peace of mind though.

 

[nate379]

I do 250hr OIC on almost everything.
Probably could go longer on some, but oil is cheap compared to an engine.
Works out to 10k mile "equivalent"

Hours because it tracks use better. Truck might idle 5hrs and not move.

Work truck for example has about 11,000hrs but only 23,000 miles

 

[wpod]

What is Ford recommendation for severe service?

 

[cptbarkey]

This is basic Blackstone Labs advice, based on thousands of UOAs on that engine. “Change the oil on mileage, not time.”

Your engine doesn’t have an open breather like a 1950s tractor, hence the risk of condensation is nil.

 

[Plawan]

This is basic Blackstone Labs advice, based on thousands of UOAs on that engine. “Change the oil on mileage, not time.”

Your engine doesn’t have an open breather like a 1950s tractor, hence the risk of condensation is nil.

Yep, once your out of warranty time on OCI is of no real consequence. Go by Mileage or hrs.