Oil change interval

raydav

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I have a turbo 7.3 IDI that weighs 9K# and an 01 PSD that weighs 11.4K#. Both run Shell Rotella T6, and PSD filters. Neither uses enough oil to notice.

If I change the oil and then drive nine thousand miles in six weeks, when should I change the oil again?

This is not a hypothetical question. The IDI and PSD did Hot Rod Power Tours in 2018 and 2017 respectively. And both did about the same time and distance referenced above.
 

snicklas

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Honestly I would change it when you return. If you don’t want to change it, at least get an oil analysis done and see what condition the oil is in.

9000 miles is a lot, unless you are running a bypass filter. I change my 6.0 at 5000 ish and the IDI near the 3000 mark.

I realize your oil is all that old, but OCI’s are time or mileage whichever comes first. To be safe, if they were mine, I’d change them when I got home.
 

nelstomlinson

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We have 9 Cat 3516 gen sets at work. We change the oil every 500 hours, per the Cat recommendation. The engines have little blow-by, and are usually lightly loaded. The oil analysis always tells us that the oil is still good, and we didn't have to change it.

If we assume that operating the generator is equivalent to cruising in our trucks at 50mph, 500 hours is equivalent to 25,000 miles. It might be interesting to run your 9,000 mile trip, and then get the oil analyzed.
 

raydav

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at least get an oil analysis done and see what condition the oil is in.

I am going to make a serious attempt to find a local oil test service. I have six vehicles that run and three more scheduled to go on-line. And the use of each varies greatly, and changes from year to year.
 

Hydro-idi

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I wouldn’t worry about it all that much. Just make sure you got oil in the engine lol. Check every few days when you fill up. Change it when you get back from your trip & call it good.
Oils nowadays are of much better quality than they used to be, and people often tend to overthink what oil to use and/or OCI’s.
 

79jasper

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I am going to make a serious attempt to find a local oil test service. I have six vehicles that run and three more scheduled to go on-line. And the use of each varies greatly, and changes from year to year.
I know a guy you could talk to....

Sent from my SAMSUNG-SM-G930A using Tapatalk
 

Shadetreemechanic

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My experience is the motor will tell you when change is overdue. Oil consumption will stay normal to a point, and then engine will start to eat oil. At that point you have used up the additive package and you are (in my opinion) about 1000 miles overdue.
I would try the full 9000, but woulds start to watch the oil level after about 6K. I bet they will jump in consumption before you get to the full 9K but maybe not. I know guys running schaeffer oil who swear by 12K oil change intervals.
 

raydav

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My experience is the motor will tell you when change is overdue. Oil consumption will stay normal to a point, and then engine will start to eat oil. At that point you have used up the additive package and you are (in my opinion) about 1000 miles overdue.
I would try the full 9000, but woulds start to watch the oil level after about 6K. I bet they will jump in consumption before you get to the full 9K but maybe not. I know guys running schaeffer oil who swear by 12K oil change intervals.

We have been doing these 9K trips for at lest a decade; mostly with the 89 IDI, this year with the 93 replacement, and 2015 and 2016 with a 351W in a 65 Mustang. I don't recall ever using enough oil to get my attention.

I also use Rotela T6 in my gas engines.
 

Thewespaul

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We have been doing these 9K trips for at lest a decade; mostly with the 89 IDI, this year with the 93 replacement, and 2015 and 2016 with a 351W in a 65 Mustang. I don't recall ever using enough oil to get my attention.

I also use Rotela T6 in my gas engines.
I bet we’ve met at some point, I was there 2015 and 2016 in a newer mustang. Auto/turbo car all black.
 

Mr Dieselcraft

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You should look at putting a centrifuge on the engine and doing oil analysis. Centrifuges have seen the doubling of oil life. A centrifuge will remove huge amounts of soot from the oil that the filters do not get.
 

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