I hate the "Time Based" Oil Life Monitor
10-09-2018, 11:03 AM
#1
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I hate the "Time Based" Oil Life Monitor
So I normally change my oil every year when I get my car inspected. And my car usually has 3500 to around 4500 miles per year at the time of inspection. As a comparison at that point my C6 would have said I had ~40 % or more life left. So this year at about an 11 month interval since the last change and 3000 miles driven, I'm down to 2% life left on the oil. That's absurd.
10-09-2018, 11:13 AM
#2
No, its the recommended change interval. Feel free to disagree with GMs recommendation, but the monitor is working as designed.
I have never relied on these monitors on past models as they were inaccurate to borderline useless. This one actually works.
I have never relied on these monitors on past models as they were inaccurate to borderline useless. This one actually works.
10-09-2018, 11:30 AM
#3
Melting Slicks
Just get in the habit of changing it at the end of the season (if you live where seasons change) and you wont have anything to worry about. If you live in a warm climate area, then pick a date and then always change it on that date...SIMPLE! Your not driving enough to not go by a date...just ignore the monitor and reset whenever needed. Remember GM states the oil should not go beyond 1 year without changing - REGARDLESS of the mileage...
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10-09-2018, 11:52 AM
#5
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I do change it once a year at inspection time. I feel that the "Oil Life Monitor" is overly conservative.
10-09-2018, 11:53 AM
#6
Safety Car
OK... if it makes you feel better in 6 months reset it, then it will tell you that 50% is left when your inspection is due. Problem solved.
10-09-2018, 11:55 AM
#7
Melting Slicks
2% is GM's absurd opinion about the oil life. The oil is probably good for many more years at that mileage rate. Your car is one of my favorites.
Last edited by proexpert; 10-09-2018 at 11:55 AM.
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Walt White Coupe (10-09-2018)
10-09-2018, 12:14 PM
#8
Race Director
I understand Walt's beef here though, because if he's only putting 3500 to 4500 miles a year on his car he can easily do 12 month oil changes, but with time being added to the algorithm now it wants him to change it after only 11 months. So for some people if they followed the OLM to the letter like this, and they were previously doing oil changes at the same time each year (either because of inspection or to do it just before winter storage), this now makes things a little more inconvenient. In cases like this I would say to reset the OLM but wait to change the oil until the actual one year mark, then reset the OLM once again.
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10-09-2018, 12:30 PM
#9
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Actually, I have been ignoring the monitor and just doing my normal yearly oil change. But I'm sure there are some of the more **** people here following the monitor to the tee.
10-09-2018, 12:33 PM
#10
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I figure if it's under warranty, do what it says. If it is out of warranty, do what you want. Of all the things it is possible to "hate" about a Corvette, this is not something I would ever pick.
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speedlink (10-09-2018)
10-09-2018, 12:53 PM
#11
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I love the car, maybe dislike would be more accurate.
10-09-2018, 01:23 PM
#12
I like it a lot.
I drive my car year-round in almost daily use and keep the revs up more than the average driver. Thus, I know the OLM is clearly doing it's job well, because I'm generally only getting 5K miles between changes with the OLM winding down. That's about 5 months for me. I change it when it's approximately 20%.
Type of use and time are all important factors as to when a change is necessary for max engine protection and life, and the OLM algorithm does a terrific job of factoring all that in.
I drive my car year-round in almost daily use and keep the revs up more than the average driver. Thus, I know the OLM is clearly doing it's job well, because I'm generally only getting 5K miles between changes with the OLM winding down. That's about 5 months for me. I change it when it's approximately 20%.
Type of use and time are all important factors as to when a change is necessary for max engine protection and life, and the OLM algorithm does a terrific job of factoring all that in.
Last edited by Foosh; 10-09-2018 at 01:45 PM.
10-09-2018, 01:43 PM
#13
Melting Slicks
I change mine annually right before storage, which is Nov. 1st. I added about 5,000 miles this Summer, mostly highway miles, and it's down to 8% on the monitor. By the end of October it will time out to 0 which would be where I expect it to be for the annual change.
10-09-2018, 02:21 PM
#14
It's a bunch of crap. I only put 4K on mine in the last 14 months, oil is in great shape. I will ride it for a few more months before I have it changed.
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jimmie jam (10-10-2018)
10-09-2018, 02:21 PM
#15
Burning Brakes
I agree with the OP. We have two Lexus', and they advise to change the oil every 10k miles - no time frames. For us, that can be over two years between changes, and it hasn't resulted in any problems. The cars are an '07 with 92k miles, and a '10 with just shy of 70k miles (will have its oil/filter changed within a month).
I will also follow the 10k miles schedule on the C7 after the warranty expires, however, I have no doubt the car would have no oil-related issues at the 10k mile mark regardless of what the OLM advises. In almost 60 years of driving, obviously most of them prior to pre-synthetic oil availability, none of my dozens of cars dating back to a '58 VW has ever had an oil-related problem.
I will also follow the 10k miles schedule on the C7 after the warranty expires, however, I have no doubt the car would have no oil-related issues at the 10k mile mark regardless of what the OLM advises. In almost 60 years of driving, obviously most of them prior to pre-synthetic oil availability, none of my dozens of cars dating back to a '58 VW has ever had an oil-related problem.
10-09-2018, 03:05 PM
#16
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So, simply reset it and go on. 
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Mike Mercury (10-10-2018)
10-09-2018, 03:17 PM
#17
I have never changed oil as often in any car that I owned compared to my 2017 Stingray.
1st at 3000 miles (65% left showing on oil monitor) in fall 2017 and put away for winter
2nd at 7100 miles (56% left showing on oil monitor) in spring 2018
3rd at 11500 miles (44% left showing on oil monitor) in fall (today actually) 2018 going to put away in a few weeks for winter
4th at (estimating mileage here) 14500 miles summer 2019 ---> this will be my last free oil change from GM at the dealership.
I must say that my oil always looks very clean every time I check it and the car runs great.
In 2020 I will start doing my own oil changes once a year.
1st at 3000 miles (65% left showing on oil monitor) in fall 2017 and put away for winter
2nd at 7100 miles (56% left showing on oil monitor) in spring 2018
3rd at 11500 miles (44% left showing on oil monitor) in fall (today actually) 2018 going to put away in a few weeks for winter
4th at (estimating mileage here) 14500 miles summer 2019 ---> this will be my last free oil change from GM at the dealership.
I must say that my oil always looks very clean every time I check it and the car runs great.
In 2020 I will start doing my own oil changes once a year.
10-09-2018, 03:49 PM
#18
Like Foosh, I drive my car year-round and almost daily, and I lean on it exuberantly. This translates to oil changes approx every 7 - 8 months.
Just my opinion, but if the OLM is conservative that's fine with me. I'd rather be changing out oil that still does its job, than oil that hasn't been. Also, warranty.
Another note. GM owns the patent for the OLM used in most vehicles. See https://patents.google.com/patent/US20120044077. I would imagine that the inputs and weights given to the various parameters are specific to each application. So what you experienced in a C6 won't be the same as what you see in your C7, or any other car.
Just my opinion, but if the OLM is conservative that's fine with me. I'd rather be changing out oil that still does its job, than oil that hasn't been. Also, warranty.
Another note. GM owns the patent for the OLM used in most vehicles. See https://patents.google.com/patent/US20120044077. I would imagine that the inputs and weights given to the various parameters are specific to each application. So what you experienced in a C6 won't be the same as what you see in your C7, or any other car.
10-09-2018, 07:58 PM
#19
Race Director
Looks like GM wants to go back to the 3000 mile oil changes ("cheap insurance.")
I also know the oil is not shot at 5000 miles, and the annual change is ridiculous.
I've got about 4500 miles on my oil, and changed it myself on 10/10/17.
The oil looks pristine on the dipstick. Sure, I better change it.
I will change it before winter storage, but it is a waste.
I also know the oil is not shot at 5000 miles, and the annual change is ridiculous.
I've got about 4500 miles on my oil, and changed it myself on 10/10/17.
The oil looks pristine on the dipstick. Sure, I better change it.
I will change it before winter storage, but it is a waste.
10-09-2018, 08:28 PM
#20
E-Ray, 3LZ, ZER, LIFT
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PS: E
My 1988, 1993, 2008 owner’s manual have ALL said change at xxx miles OR if it had one when the OLM said OR “1 year” WHICHEVER OCCURS FIRST!
In fact I’ll quote my ‘93 40th Anniverstity Vette Owner’s Manual:
It stated: “Change at 7500 miles OR ONE YEAR WHICHEVER OCCURS FIRST.”
ALSO, it stated: “If most driving is under 4 miles change at 3000 miles or THREE MONTHS WHICHEVER OCCURS FIRST!”
DETAILS:
You’re not changing oil only because it wears out! Starts are the worse thing for oil and your engine. Blowby from the extra piston to cylinder wall clearance causes combustion products to pass the cold aluminum pistons untill the ~2500 F combustion temps heat them up and they expand. Water is a combustion product. It mixes with sulfur and other “stuff” to form acids etc that cause corrosion. The OLM considers after each start how hot and how long the oil reaches temps that evaporate much of that water. It uses other factors, like engine revs etc as well. In fact mileage and time were OK because that is all we had in the past!
The ‘93 Owner’s Manual (and all other cars/trucks I have owned) stated for sever service change at ~3 months. Would you prefer that GM “guess” than actual measurements?? Recall dealers and Jiffy Lub using 3000 miles on the “when to replace stickers?” They had other motives BUT their justification was that sever service use statement. They could justify as they did not know how you drove!
My Street Rod, that mostly goes to Car Shows gets it’s oil changed once a year! I can “see those steel cylinder walls rusting from contaminated oil.”
It’s 8.2 Liter BB runs as good now as when I semi-retired and built it 18 years ago! Cheap insurance, IMO as well as GMs!In fact I do one other thing with the Street Rod folks might consider, especially those with dry sumps. Since it’s not used often and blocks things like my long ladders in the garage I avoid backing it out removing whatever and pulling it straight back in! I try to drive it ~25 miles to get the oil hot and evaporate blowby (also to have fun!). Especially for those who put few miles on the Vette driving to a store 3 miles away- probably the worse thing you can do for you car! But it’s your car do as you wish!
PS:
For folks who do change their oil once a year BUT don’t like GM just showing the time progression as it gets to a year, WHAT SHOULD THEY DO? I SURE WOULD NOT BE HAPPY IF IT DISPLYED NOTHING UNTILL SAY 5% LEFT!
I have no issues since I don’t look at the OLM display untill nearing the one year. Why do you bother?
Sorry for the long post but this has been one of my fun subjects since I got my September 2013 built C7 Z51!
Last edited by JerryU; 10-09-2018 at 09:48 PM.