coupeguyz51

I have a Z51 and recently had the oil changed...With Mobil 1
After less than 700 miles, the OLMS is telling me that I have
47% oil life remaining!!!!
That is preposterous!!!!
I have not driven her at all hard since I had the oil changed...
I mean if I drove her like the "Fast and Furious" every day,
perhaps the oil change recommendation would make sense...but
I can discern no reason for this warning other than perhaps
GM has invested in oil company stock...
The Mobil 1 is supposed to last ten times longer than that!
I am just going to go by mileage and ignore this useless OLMS...
What have been your experiences?

Kracka

It is actually a very good system. It takes many variables into account, time included.

coupeguyz51

A "very good system?"
For who?
Mobil?
The dealer,
Absolutely!
And what variable does "time" play?
It's only been a couple of months and I'm at 47%????
This OLMS is nothing but a consumer rip off!

lakemg

Are you sure that the oil life was reset when the oil was last changed?

coupeguyz51

Yes. I checked

mschuyler

This suggestion that it is a conspiracy is absurd. Relax. Wait until the car tells you it's time for an oil change before you have a conniption fit over this. Then follow it or don't. It's not required.

Last time my OLMS told me I needed an change at 7500 miles and a year, which is pretty much on the money.

Always Red Dave

Hit the reset oil button and you will be back at 100% and I do a oil change once a year with the 3000 miles I drive a year.

coupeguyz51

Well, I suspect that most people don't wait for the OLMS to get down to 0% before changing their supposedly long lasting Mobil1 oil....
they change it, unless they know like you do apparently that it is optional.

I haven't had a "time to change oil message" because I never let it get down to single digits....I mean, what is the point of having an OLMS that is wildly inaccurate other than to get you to run in and get an unnecessary oil change?

Well, I'm heading out for the evening...probably be down to 41% or less before I get home....

runner61627

I had the dealer change the oil just before I put it into winter storage in October. Just took it out and oil life is at 52%, so I'll get it changed in another two months. It is tracking just as it should based on time/mileage. I have used only two of the five (Z51) free oil changes, so no problem. If the OP doesn't agree with the system, then reset and ignore

owc6

Mine has been very consistent and gives me about 7,500 miles before the ten percent mark. I also drive ~22,000 miles a year, so I doubt it takes "time" into too much consideration for me.

mschuyler

But the rest of the story there is that you don't need to change it even if you follow it until it reaches near-zero. And you are projecting and expecting a lineal decline in the percentage. In my experience (which is not extensive, but still) it's more like a gas gauge. I have owned dozens of cars (just like y'all) and I have yet to have a gauge--way back to my 48 Chevy Fleetline--register half a tank when it really was much less than that. Full to half takes forever, and half to empty goes a lot faster.

I should really do a test next time, but my contention is that the OLMS is NOT lineal and that you actually have some time before it gets to near zero and the OnStar system starts bugging you about it with an e-mail. Mine even emails my dealer, so my dealer emails me and says, "Hey, OnStar says you need an oil change!" So I say, "OK. Fine. Come get it!" and they do, and it's free anyway (for now)

I'm thinking of killing my OnStar because it's bugging me, but on the other hand it tells me when my tire pressure is low. I find that the run-flats are terribly difficult to control. I have a good compressor and everything, but getting those run flats perfect is a real PITA. (Off topic. Sorry!)

Rooster OG

Don't change it then. It's your car, you can follow whatever guidelines you think are best.

millpond

The OLM is time dependent. It will let you know to change the oil at least once every year because that is what is required to keep your warranty in effect.

TNSQUIRE

My OLMS has been very accurate. I drive several days per week. Some short city runs and a few longer highway miles.

W88fixer

I think you are perhaps inadvertently throwing some confusion into the issue. The manual on my 2014 C7 says "The engine oil and filter must be changed at least once a year...." It also says you could go beyond a year under optimal conditions if you just looked at the OLM but the annual change drives everything, no matter how little or much you drive the car. Don

mschuyler

OK, so NOW you are saying the OLM is not accurate and that you may need to change the oil MORE often than the OLM says to? Wow! Wonder what OP, who thinks the OLM is a conspiracy to change oil more frequently than necessary and enrich the oil companies, thinks about that! And here I thought the OLM takes TIME into consideration.

I am now SO confused!

fdxpilot

Let me guess. You had your oil changed back in September, and the car has basically just been sitting since then, accumulating only 700 miles in 6-7 months. Since the OLMS takes time into account, based on the one year max change interval, 47% is about right. Now, if you actually start accumulating mileage, you may rack up 4-5000 miles before next fall when the elapsed time will cause the OLMS to reach 0.

Just as a personal example, my Z06 had its initial oil change at about 580 miles. The second change came at 9 months and 4600 miles later with the OLMS indicating 16% Oil Life remaining.

Maxie2U

You don't need OnStar to get tire pressure, you can get tire pressure via "Info" in the instrument cluster.

MikeyTX

Or, doing it the way it really should be done ............ With an accurate tire pressure gauge.

owc6

The tires are such low volume that people should be checking them quite often. It is possible to have more than a ten psi difference in a single day.

I had this when traveling from KC to Denver. I started out in a 55 degree rainstorm before dawn, and it was 95 degrees when I arrived in Denver that afternoon.

And certainly, relying on the DIC to tell you accurately the pressure when either filling up or letting air loose is not a good idea: the car does not sample often enough to get an accurate fill amount.