Engine Oil Change Indicator System - how does it calculate remaining oil life?

[Rubicon6MT]

Does anyone know exactly how the engine oil change indicator system works?

How does it determine the percentage of remaining oil life, and when the engine oil needs to be changed.

The post below mentions 350 hours of engine runtime, but I was told it’s calculated based on ignition key cycles?

I'm pretty sure the oil life is a combination of driving conditions including that 10,000 miles or 350 hrs. hell in another thread a forum member named 'The Office' idled so much he deduced that every 8 hrs of idle you loose 4% of your oil life. That would prove that the 350 hrs engine run time is definitely being utilized for the Oil life indicator. Basically change the oil when you want to but If you are worried about going over 350 hrs don't be, the jeep will let you know.

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[DylanM]

From the service manual:

 

[ShadowsPapa]

Does anyone know exactly how the engine oil change indicator system works?

How does it determine the percentage of remaining oil life, and when the engine oil needs to be changed.

The post below mentions 350 hours of engine runtime, but I was told it’s calculated based on ignition key cycles?

Most of the above is incorrect.
It's VERY scientific and accurate. In fact, Lake Speed Jr. has used actual oil analysis to compare.
It uses a lot of factors including idle time, time at certain temperatures, load on the engine, heat of the engine, stops and starts, cold starts and a list of things too long to get into.
Trust it, 100%

I note when I tow, my OLM drops the oil life a lot more quickly than when I'm not towing - because it senses the load on the engine (monitors torque).
Key cycles would be for cold starts. Cold starts and short drives are bad, so it dings your oil life for that as well.

 

[Lost1wing]

What device on our 3.6l pentastar engine determines the Ethanol %? Sending unit? Temperature sensor?

 

[ChrisNLA]

What device on our 3.6l pentastar engine determines the Ethanol %? Sending unit? Temperature sensor?

In an LS engine there is a sensor in the fuel line to determine ethanol content. Im sure on a Pentastar its the same, though I thought the Gladiators were not E85 capable (only E15) and so not sure if they have a sensor.

 

[ShadowsPapa]

In an LS engine there is a sensor in the fuel line to determine ethanol content. Im sure on a Pentastar its the same, though I thought the Gladiators were not E85 capable (only E15) and so not sure if they have a sensor.

I'm guessing not, based on this from one of our Jeeps a while back:

Low Ethanol PWR Enrich Flag: No
Low Ethanol Therm Management Flag: No
Ethanol Gas For Sure: No
Ethanol Mode: No
Ethanol - 0% Blend Direction: No
Ethanol - 85% Blend Direction: No
Ethanol - Open Loop Fuelling: No
Ethanol Fine Tune Complete Previous: No
Ethanol Fuel Volume Changed: No
Ethanol Low Fuel: No
Ethanol Trigger On Fuel Volume Fault: No
Ethanol Trigger During Learn: No
Ethanol Learn: Disabled
Ethanol Course Update Ready to Learn: No
Ethanol Course Update: Not completed
Ethanol Fine Tune: Not completed
Actual Torque: 0.84 Nm
Potential Torque: 78.16 Nm
Target throttle position: 2.56 V
Electronic Throttle Control (ETC) Motor Directional Duty Cycle: -20.67 %DC
Electronic Throttle Control (ETC) Motor Duty Cycle: 20.67 %DC
Throttle position sensor 1: 2.58 V
Throttle position sensor 2: 17.42 V
Accelerator pedal sensor 10.44 V
Accelerator pedal sensor 20.22 V
Accelerator pedal position: 0.00 %
Brake switch 1: Released
Brake switch 2: Released
H-Bridge Circuit: Enabled
Ignition Run/Start Switch: On
Throttle Flow Adaptive: 0.13 g/s
Throttle Flow Multiplicative Adaptive: 2.00
PHI Adaptation Value: 0.00
Calculated MAP: 46.59 kPa
Ethanol Percent: 0.00 %
Turbo Boost Timer: 0.00 ms
Throttle Inlet Pressure: 0.00 kPa
Throttle Inlet Pressure Voltage: 320.34 V
Turbo Airport Mass Flow: 3.45 g/s
Turbo PRatio: 1.00
Turbo Torque Count: 0
Turbo Speed: 65535 rpm
Turbo Wastegate Duty Cycle: 200.01 %DC
Time since Run/Start: 45 sec
___________________
First Service Freeze Frame:
___________________
Fault code: P0303
PCM Mileage since MIL On: 0.00 miles

 

[g2020]

This is a good place for this reminder.

Motor Oil & Oil Filter Service Intervals

Recommended manufacturer specifications: Material standard MS-6395, API Certified, and SAE 0W-20

- Many mixed-use (off-road & daily driver) Gladiator owners change the oil & filter at 5,000 mi or 1 year, whichever comes first
- A good interval for a daily driver is 7,500 mi or 1 year, whichever comes first
- Always change both motor oil and oil filter (as noted on p. 252 below)

1. Under Any Conditions
- Change oil & filter within 500 mi after Oil Change Indicator System message illuminates (no grace period after 500 mi / 500 mi is the grace period)
- Triggered as early as 3,500 mi
- Never more than 1 year or 350 hours, whichever comes first

- In case the Oil Change Indicator System malfunctions (stranger things have happened), follow the limits for Severe Duty or Normal Driving

2. Severe Duty
- Limit of 4K mi, 1 year, or 350 hours, whichever comes first

3. Normal Driving
- Limit of 10K mi, 1 year, or 350 hours, whichever comes first

Viscosity grade: One of the revisions to the 2020 Jeep Gladiator owner's manual, in the online version, is that five API Certified motor oil grades are listed. However, SAE 0W-20 is recommended in the next paragraph on the same page (p. 251, below).
- For an analysis of motor oil viscosity grades, see Motor Oil Compiance Funnel

Engine break-in: If you have a new Gladiator, also see Engine Break-in Advice from the Owner's Manual

From 2020 Jeep Gladiator Owner's Manual, 2nd Edition (published in 2019)

From 2020 Jeep Gladiator Owner's Manual, online version (downloaded on April 16, 2025)

Advice on oil filter:

 

[ShadowsPapa]

The oil life monitor handles that - it's smarter than most drivers and owners. It tracks how the thing is used. Proven technology over many years, and supported by Lake Speed Jr. and his oil analysis.

Anything else muddies the waters.

 

[WILDHOBO]

Most of the above is incorrect.
It's VERY scientific and accurate. In fact, Lake Speed Jr. has used actual oil analysis to compare.
It uses a lot of factors including idle time, time at certain temperatures, load on the engine, heat of the engine, stops and starts, cold starts and a list of things too long to get into.
Trust it, 100%

I note when I tow, my OLM drops the oil life a lot more quickly than when I'm not towing - because it senses the load on the engine (monitors torque).
Key cycles would be for cold starts. Cold starts and short drives are bad, so it dings your oil life for that as well.

Yep. This exactly. If you want to baby your engine, which I do from a maintenance perspective, just change it at 30% or 25% instead of close to zero. I towed 2700 miles the day after an oil change and it’s already down to like 30%. Normally I’ll get to 5-6k at 30%.

 

[ShadowsPapa]

Yep. This exactly. If you want to baby your engine, which I do from a maintenance perspective, just change it at 30% or 25% instead of close to zero. I towed 2700 miles the day after an oil change and it’s already down to like 30%. Normally I’ll get to 5-6k at 30%.

Interesting - that's what I do. I could go to 0% remaining, but - I generally get around 30% and decide - close enough. Mine was down to about 10% one time and I had maybe 7,000 miles on it, "ideal", low load conditions, it's roughly 10% for every thousand miles - IDEAL easy conditions.

I do watch how the monitor behaves when I'm doing various things with it, and it's amazingly "smart".
It sensed the torque, and other factors, and "knew" you had used it a bit harder.
There's a whole set of posts on it in the forums somewhere, I think even Hootbro chimed in on it back then.

 

[WILDHOBO]

Interesting - that's what I do. I could go to 0% remaining, but - I generally get around 30% and decide - close enough. Mine was down to about 10% one time and I had maybe 7,000 miles on it, "ideal", low load conditions, it's roughly 10% for every thousand miles - IDEAL easy conditions.

I do watch how the monitor behaves when I'm doing various things with it, and it's amazingly "smart".
It sensed the torque, and other factors, and "knew" you had used it a bit harder.
There's a whole set of posts on it in the forums somewhere, I think even Hootbro chimed in on it back then.

Yep. I don’t know why some people don’t trust it. It’s very easy for a computer that is already tracking metrics like this.

 

[ErylFlynn]

That is some dam useful information. I been wondering on when to change my oil, luckily I just did. 3200 miles on it, BUT it was last October 4th I changed it. Yea I don't drive much. So I came in under the 1 year mark. I will be sure to change before 1 year next time as well. The indicator showed 50% oil life, which I was a bit surprised as I don't do a lot of long trips. 10 minute or more to my Jiu-Jitsu class and Home Depot/Lowe's runs which are about the same.

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