Miles between oil change: A data point

[roaniecowpony]

Since you're looking to extend your OCI, you might want to consider the breakdown of the oil in it's performance for HTHS. I believe HTHS is what protects your cam/rocker system. 0w20 is very low on HTHS and running it long intervals takes it lower. Consider moving to a 5w30 with improved HTHS for extra margin in long OCIs.

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[Pape]

You are aware that your CST at 100C is the one of a 0w16 ?

 

[rk911]

It's hard to tell if you are joking or not. The whole idea was to be data driven and not just going with your gut.

Nope, not joking. I repeat...you can't change oil too often. Apart from a few that we just tired of all of our vehicles had 100,000+ miles when we sold or traded them. My gut works just fine.

 

[azwjowner]

Lots of frequent oil changers jumping in here. I probably wouldn't go much past 7500 miles but that's because I don't trust Jeep.

I do 10k intervals on my Honda. Tons of people do. And all the engines last hundreds of thousands of miles with zero problems.

It's not the oil or the oil intervals, it's Jeep engineering.

 

[NWJeepr]

Nope, not joking. I repeat...you can't change oil too often. Apart from a few that we just tired of all of our vehicles had 100,000+ miles when we sold or traded them. My gut works just fine.

I once read that changing too often can be too often. The reason given (without proof) was that fresh oil contains very high detergent levels and is slightly alkaline to neutralize acid that forms during the oil's service life in the engine. Having anything too acidic or too alkaline in the engine is equally bad for wear surfaces.

Again, something I read without proof, but also something to consider for those who want to "science" their oil change frequencies.

 

[Vinman]

I’ll stick with my 3,000 mile change schedule.
As far as manufacturers recommendations, I had a few Cummins powered Rams over the years, My ‘11 spec’d 12,000 km oil change intervals and my ‘15 spec’d 24,000 kms.
The only difference was the ‘15 had increased power, about 50% more tow capacity, 3.42’s vs the ‘11’s 3.73 gears.
Same engine oil spec and same capacity.
Now how did they double the mileage intervals?

 

[LDSSILLS]

Now how did they double the mileage intervals?

I believe they get away for two reasons in gasoline engines.

1) Gasoline today contains heavily saturated detergent, therefore cylinders remain clean and valves seat much more efficiently. IE: less carbon is made.

2) Electronic ignition changed the world! No more points causing plugs to fire early or late, thus nearly 99.9% of the fuel is burned. Sensors also work with the computer in micro seconds to stop cylinder ignition issues, thus pinging is nearly 100% gone.

Both of these lead to less carbon buildup. Less carbon means cleaner oil, cleaner oil means a longer lifetime.

In my day points, timing and plugs were all part of the oil change and it happened every 3,000 miles. Get your points a little to wide or narrow and the engine coughed up carbon. Get timing off just 5 degrees and valves dumped the carbon into the crank case. Hell I have seen crank case fires that blew the pan off in my day.

 

[roaniecowpony]

I believe they get away for two reasons in gasoline engines.

1) Gasoline today contains heavily saturated detergent, therefore cylinders remain clean and valves seat much more efficiently. IE: less carbon is made.

2) Electronic ignition changed the world! No more points causing plugs to fire early or late, thus nearly 99.9% of the fuel is burned. Sensors also work with the computer in micro seconds to stop cylinder ignition issues, thus pinging is nearly 100% gone.

Both of these lead to less carbon buildup. Less carbon means cleaner oil, cleaner oil means a longer lifetime.

In my day points, timing and plugs were all part of the oil change and it happened every 3,000 miles. Get your points a little to wide or narrow and the engine coughed up carbon. Get timing off just 5 degrees and valves dumped the carbon into the crank case. Hell I have seen crank case fires that blew the pan off in my day.

Don't leave out electronic fuel injection. This probably accounts for a large share of long OCIs as well as long engine life

 

[JT23JL]

I have 303,000 miles on my 2002 Tahoe. Engine runs great. The average oil change interval over its lifetime is 7,080 miles. The average oil change interval over the last 100,000 miles is 9,200 miles.

I used Mobil-1 and Pennzoil 5W-30 synthetic oils for the first 100,000 miles. I have used Walmart SuperTech 5W-30 synthetic for the last 200,000 miles.

For me, changing the oil every 3,000 miles would have been a waste of my time and money.

 

[roaniecowpony]

I have 303,000 miles on my 2002 Tahoe. Engine runs great. The average oil change interval over its lifetime is 7,080 miles. The average oil change interval over the last 100,000 miles is 9,200 miles.

I used Mobil-1 and Pennzoil 5W-30 synthetic oils for the first 100,000 miles. I have used Walmart SuperTech 5W-30 synthetic for the last 200,000 miles.

For me, changing the oil every 3,000 miles would have been a waste of my time and money.

It's an LS. 300k is right down the middle. Boring.... ... a very good kind of boring

 

[2019JLUS]

I see lots of threads about how often to change oil, but most posts seem to be based on gut feelings. As an experiment I decided to use the Jeep's oil monitor as my guide since I see a lot of scoffing at that metric. I didn't let it get all the way down to zero, but I did get it down to 1%. This meant an oil change after 8820 miles.

An oil sample was sent to Blackstone. It's nice having data to take the ambiguity out of a decision. I'm going to take the advice and go 10,000 miles next round. But I might be giving my Jeep calcium supplements.

Your approach is solid—relying on actual data to make maintenance decisions removes guesswork. From the report, your engine seems to be performing well within normal limits, even after 8,820 miles. The absence of excess wear metals or contaminants supports extending your interval to 10,000 miles.


The calcium content looks normal, as it’s part of the oil’s detergent and dispersant package. Unless you switch oil brands or notice something unusual in future reports, it shouldn’t need supplementation.


If you’re sticking with the Jeep’s oil life monitor, this data should boost your confidence in its algorithm. Anything else about the report stand out to you?

 

[smokeythecat]

Anything else about the report stand out to you?

Hm. No. What did I miss?!

I was joking about the calcium, by the way.

 

[Kracka]

@smokeythecat what oil filter did you run?

 

[smokeythecat]

@smokeythecat what oil filter did you run?

The OEM Mopar. I think the number is 349.

 

[DRVMN]

I believe in the end, everyone has to do what makes them sleep best at night. I change my oil and filter every 5,000 miles. It's an easy interval to remember, and the cost of oil plus the Mopar filter is under $35 and easy to do. I believe in data as well, and the story it tells. It all comes down to personal choice. I don't argue politics, religion, or oil/filter changes!

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