coupeguyz51

My baby was born 10/9/13....not driven particularly hard, not tracked at all...yet as I approach 3k miles, the display says "18% oil life remaining"
What does that mean? What is is based on?...seems to be based on the old change your oil every 3500 miles that used to be true in 1970, but with modern synthetics why is it giving off that message?
I'm taking her in for an oil change in a couple of weeks, but am still curious about the low mileage oil life expectancy, if, in fact, that message means anything close to reality....

W88fixer

As far as I know, it’s based on temperature, rpms and probably other factors. Lots of short drives w/o full warmup will decrease oil life more quickly than normal. I’m sure some will amplify what I have said. Don

Kracka

In your case is has more to do with time than anything. Oil should be changed once a year regardless of mileage and it appears the indicator is programed with that in mind. You get 4 free oil changes from Chevy in the first 2 years/24k miles so at your pace you may want to just start getting them every 6 months to get the most out of the plan. I was at 15% after 6500 miles in 3 months.

talon90

When the car is driven the oil life monitor uses an algorithm which calculates oil life based on ignition cycles, oil temperature and rpm's.

It is basically looking at the factors that cause oil to degrade.

Oil should also be changed once per year regardless of oil life percentage or miles.

It would appear that they have added an algorithm that takes time in to account. The manual has always stated that regardless of all other factors we should change the oil once per year.

jerryv

I'm not sure the car is 'aware' of the date .. I've certainly not seen any indication that it knows how much time has elapsed since it was built .. But I guess it could ..

How do you drive your car? Do you make a lot of short trips? Not getting the oil good and hot is probably the biggest factor in shortening its life ..

Kracka

The car has a calendar in the infotainment system, it is aware of the date This is nothing new, systems like this have been around for about a decade...and they just keep getting smarter.

Zymurgy

So, if it actually uses that date, it would seem that one could set the date ahead and make the oil life indicator go below the 20% that some dealers require for the free change.

owc6

Now, that's thinking outside the box!

jerryv

Duh .. I should have checked the owner's manual first .. you're absolutely right.

coupeguyz51

Thanks for the info guys...was just curious as to how the car's computer made these calculations...

ZOHSIC

I understood it to be based on a count of full ignition cycles. Stop, start, temp etc. After spending a very long time in my car last weekend and it having had a fresh oil change, I notice the monitor degrage 1% every time I finished a cruise. (which included a few pulls) Starts at 99% after the oil change, and was down to 96% four days later.

ZOHSIC

I also have an SUV that has gone up to one year or more with little driving and the % counter did not factor in time. (it's a Ford though)

coupeguyz51

So, let me get this right...are you saying by "a count of full ignition cycles" that every time you start and stop the car, the % of oil life remaining drops by 1%?

If so, that is total bs...no, not doubting your report, but if the feature does that, then if, hypothetically, I went out and started and stopped my car 100 times after an oil change it would say that I had 0% oil life then that is simply a scam to get you to change your oil more often than needs be....if I fill up with Mobil1, I expect at least 5k miles out of it no matter how many times I start and stop the engine...

JerryU

For what it’s worth found the following info: the Oil Life System (OLS) monitors vehicle’s speed, engine temperature, personal driving habits, and the area’s climate conditions to define when to change oil.
A project engineer in GM's fuels and lubricants group was quoted saying, "We are very confident in the accuracy of the system. The average recommendation from the system for GM vehicles is 8,500 miles.”
Other publications sent oil out for analysis when the indicator said it was time to change and found the indicator was conservative and there were a few thousand miles left per the oil analysis measure. It appears a key to get longer change intervals is not to make short trips and to ensure the oil is always up to temperature on each drive cycle. If that is not possible than expect shorter change intervals. I wonder that the C7 is monitoring humidity for the fuel system, if the humid weather we have where I live in SC will also shorten change interval recommendations? Since I live 15 miles from town and seldom drive less than 10 miles I never approach a low value before changing. Regardless of miles and oil life value the owner’s manual notes oil and filter should be changed every year.

thrilled

Mine is 2800 miles.Oil life 80%.I live in A small town.I use it just about only on small trips.
Shift at around 3000-4000 rpm's.I don't have any idea why my oil life is so high.

CRABBYJ

Another data point.

Interesting that my C7 built 10/15/2013 and driven very much as posted by the OP, also is now at exactly "18% oil life remaining" having just reached 2150 miles. It was at 22% ~ 1950 miles yesterday prior to starting out for Corvettes at Carlisle with the round trip just over 200 miles. Time to call my Dealer for the first change. They refused to do it free until <20%. I need the reflashes for early VINs as well.

I know, I need to drive it more. Being retired It's not a DD nor will I do local shopping with it.

coupeguyz51

Very interesting CrabbyJ!

Went out to Carlisle today...300+ mile round trip...
btw, that is a much overrated event imho...
yes, there are some cool cars on display, and
yes it was the last day, but seemed like nothing but
a flea market swap meet and tshirt sales event... anyway...

Started out with "14% oil life remaining" and when
I got home, it said the exact same thing!!

I'm thinking that I'm just going to change the oil
every 5k with Mobil1 and not pay any attention to
that "oil life remaining" useless pos program says....

Pocket Aces

I'm sure its based on mileage and a number of other factors such as max RPM and average RPM and average speed. I would hope they program it to be more conservative during the break in period. I remember having an LS1 ram air Trans Am that actually burned oil in its first 7.5K miles due to piston ring seating but after that the oil was fine.