So, I checked it today. I was curious how it was looking compared to the miles I've put on my car since getting the oil changed. I switched to synthetic when I had it changed and it reads I have 56% oil life left. However, I've put a bit over 3,000 miles on my car since. This brings up my questions.

Did my Monte recognize that I switched to synthetic? How is that possible? In what way(s) is the oil life measured? Thanks!

 

The GM Oil Life System analyzes the engine's temperature, revolutions, and speed to calculate the rate of engine oil degradation and determine when an oil is nearing the end of its life.

So perhaps the synthetic changing the temperatures allowed it to know?

 

i believe the oil life is based on engine RPMs. therefore, if you do lots of city driving which entails more shifting and your RPMs reving up, your oil life monitor will go down faster. likewise, if you do lots of highway driving, you get more miles on your oil change. my mom's 09 malibu and my dad's 06 silverado go to almost 7-8k (highway miles) on conventional oil so i don't think it has to do with the oil being synthetic or conv, just engine RPMs to my knowledge.

my OLM behaves just like you described. i usually get 5-6k before it goes to 0%, but then i just wait til i get 7500 miles to change the oil. i wish it would be longer, but letting my car warm up and idle in the winter doesn't help that cause either.

maybe there is a GM tech lurking around the MCF somewhere that can shed some light on the OLM...

 

Hmmm... Interesting. Thanks a lot for the info.

 

I agree that it has nothing to do with the kind of oil you put in, its calculated based off those engine variables and will vary with how the car is used.

Personally, I think its too long in my opinion, but thats just me.

 

since i removed my factory radio, how can i check and reset all that stuff? i write the mileage on my oil filter when i change it but i'm just curious.

 

jimbo try this, i did a search on here and this is what i found, hope it works
RE: In dash monitor??
The oil life is reset by turning the key to acc and pushing the gas pedal down 3 times. Low Tire pressure is by Key to acc and pull the headlight button to parking and back off 3 times.

 

It's not too long at all. On my 01 Camaro my "Oil change light" would come on about every 5k. When I would change the oil it would usually still be fairly golden, but just a little darker. On my Avalanche it would do about 6k per oil change, and the oil looked the same.

That old rule about every 3k for a change is complete BS put out by oil companies to make more money. One time I decided to wait 6 months to change the oil, putting almost 12k on the oil in the car. When I changed it, same as the other two vehicles, still gold...just darker.

 

i tried all that methods and it never worked for me. when i had my after market radio install i bought a separate harness and everytime when i need to reset something i plug in the factory radio. that works way easier now.

 

The car can not tell your using synthetic, that is for sure...

But the OLM in the new GM cars is VERY reliable. It calculates the oil change interval on much more than JUST RPM alone. Temperature, RPM, number of starts, etc, all play a role in the OLM % of oil life.

Personally, even though the OLM will go 7-8K on conventional, thats to long for my comfort level, I would do every 5K changes on conventional, but on synthetic oil, 7-8K is NOT to long...my OLM goes off every 8-9K, and thats when I change my oil with Mobil 1...the oil is always a golden brown color.

The 3K oil change thing is a bunch of smoke being blown up everyones butt by the oil companies, and quick lube shops...Back in the day, maybe it was true...but with todays oils, even conventional, it is a total bunch of bull. Even the Pontiac dealer told me this one time when my moms Bonneville was in the shop getting the intake gasket fixed.

He said, your engine looks really good internally, what are you using for oil? I told him Mobil 1, and said we only put synthetic in it...he said that is great, but even conventionals now days are good, and there is no need to change your oil every 3K...