: Synthetic oil life?



Qnsryck
09-30-09, 10:20 PM
I changed my fluids to Amsoil about 3K miles ago and now I'm getting the message that I need to change my engine oil. I don't know what triggers the dash message but I was thinking the Amsoil lasted much longer than the usual 3K change. Do I really need to change it?

Caroutisine
09-30-09, 10:45 PM
Did you reset the oil life monitor when you changed the oil?

SlvrBullIT
09-30-09, 10:46 PM
You didn't reset the oil life monitor in the DIC. At the oil life setting holding down the reset button resets to 100%.

Jeffrey
10-01-09, 07:03 PM
Hi,

Is the V only accurate on Mobil 1 life or will it accurately measure the life of all major brands?

Best regards,
Jeffrey

Looney100
10-01-09, 07:40 PM
I suspect the engine oil life indicator is much less sophisticated than many may think. My guess is it just takes note of how much idling you do, engine temps, mileage, throttle position, etc. and guesses how much life is left with no regard to the type of oil you're using.
The system doesn't have any built-in engine oil analysis probes, etc. so it really has no idea how the viscosity, etc. is - just making an educated guess based on your driving habits

tedcmiller
10-01-09, 08:42 PM
The engine oil life warning is a program that checks the engine RPM and the engine temperature and computes the remaining oil life based primarily on these two parameters. It assumes a good grade of oil but does not distinguish between synthetic or petroleum based oils. Typical mileage between 100% and 0% oil life is 7 to 8 thousand miles. On earlier models, a warning would be displayed when the oil life reached 10% and then a warning would be displayed when the oil life went to 0%. Now only the 0% warning is displayed. Most people assume the program that computes remaining oil life is more sophisticated than it actually is.

Qnsryck
10-01-09, 09:23 PM
Thanks for all the help. I did not reset the notification. I guess I figured a system that is so smart to figure lubrication efficacy would know it had a clean and pristine lubricant in it. I guess that corroborates with the posts that suggest the "oil life" system ain't as smart as we think it is.

I still like the system because it's way better than the sticker in the windshield.

So, how do I know when the Amsoil should be changed? Does it darken as does conventional oil? Is there a litmus test for the dipstick?

Terry

Caroutisine
10-01-09, 10:26 PM
I would just reset it now, then change oil again when it indicates about 30% oil life left.

GM-4-LIFE
10-02-09, 01:28 AM
Thanks for all the help. I did not reset the notification. I guess I figured a system that is so smart to figure lubrication efficacy would know it had a clean and pristine lubricant in it. I guess that corroborates with the posts that suggest the "oil life" system ain't as smart as we think it is.

I still like the system because it's way better than the sticker in the windshield.

So, how do I know when the Amsoil should be changed? Does it darken as does conventional oil? Is there a litmus test for the dipstick?

Terry

Terry,

If you are running Amsoil with an Amsoil EA oil filter, you can run it for 25,000 miles or one year, whichever comes first.

I am running Amsoil 0w30 Signature Series Synthetic Oil and the EA oil filter and I will just change it at the one year mark since I don't drive 25,000 miles per year.

As long as you know how many miles you had on the car and the date when you changed it over to Amsoil, you can keep a track of it that way.

SG

Z71
10-02-09, 09:01 AM
The oil life monitor is just a computer algorithm that uses engine revolutions, engine heat cycles etc to run a countdown clock. It does not sample the oil and must be reset by the used when the oil is changed.

I have used AMSOIL for over 30 yrs. I have SSO 0W-30 in my 2009 CTS. I drive less than 10,000 miles a year so I will change oil in one year. If the OLM telling me to change oil sooner I just reset it. If often change the filter midway thru because its so easy to do and they filters are not that expensive providing you don't buy it from the dealer. I use AC Delco or a WIx.

AMSOIL has any oil filter for the CTS-V, the EaO-50 (http://www.amsoil.com/catalog.aspx?GroupID=191&zo=34396). No air filters though. The V76 engine has not AMSOIL oil filter available for it.


So, how do I know when the Amsoil should be changed?

UP to 25,000 miles or 1 yr



Does it darken as does conventional oil?

Yes, but darkened oil is not a bad thing. It just means to oil is doing it just job.



Is there a litmus test for the dipstick?

You can take white business card, put a drop of on the card and wait for it to soak into the card. Might have to leave it sit for a few hours. The observe the spot. If the spot in consistent color and had not dark ring then the oil is free of carbon and the filter is doing its job.

tedcmiller
10-02-09, 02:05 PM
It should be noted that the OnStar diagnostic reading that is normally done once a month and sent to your e-mail (if you have OnStar and have signed up for it) begins to flag the oil as needing changing after one year even if the oil life monitor has not gone to 0%.

Looney100
10-03-09, 01:40 AM
Guys, never extend your drain intervals that significantly without having the used oil tested along the way. It doesn't matter how great your oil is, if you get accumulation of contaminants, its going to fail on you.

Vrocks
10-03-09, 02:00 AM
I'm also switching to amsoil - it arrived today with the EAO-50 filter. Even though it should be safe for atleast 10,000 miles, I'm going to change it every 5-7,000. It's not overly expensive and the filter was <$15.

As far as oils go, I may try Mobil's 0W-30/40 racing oil next time (it has a higher visc rating)... similiar formula to amsoil. The main reason for why they say not to use it in a street car is due to pollution control - 2x as much Zinc and something else for extra lube / protection. I just don't know if it's engineered to last for 5,000+ miles...

GM-4-LIFE
10-03-09, 12:05 PM
I'm also switching to amsoil - it arrived today with the EAO-50 filter. Even though it should be safe for atleast 10,000 miles, I'm going to change it every 5-7,000. It's not overly expensive and the filter was <$15.

As far as oils go, I may try Mobil's 0W-30/40 racing oil next time (it has a higher visc rating)... similiar formula to amsoil. The main reason for why they say not to use it in a street car is due to pollution control - 2x as much Zinc and something else for extra lube / protection. I just don't know if it's engineered to last for 5,000+ miles...

Stick with the Amsoil. It has more proven protection over any other oil on the market and is guaranteed to provide protection for 25,000 miles or 1 year. Why waste money? Amsoil is great because I will only have to change it once a year which will save me some cash and provide some environmental benefits of not having to recycle the used motor oil and not having to recycle the oil filter frequently.

I did my first oil change back on March 11 of this year when the car had 1,908 miles on it and I have driven 6,000 miles since. I will change the oil at the 1 year mark as I know I will not have driven anywhere near 25,000 miles by that time.

SG

marktanner
10-04-09, 11:41 AM
Porsche uses Mobil 1 0-40 in their cars, including the GT3. Their recommended oil change interval is TWO years or 30,000 miles, regardless of usage (including track work; I asked at the factory). It's not the quality of the oil that's driving the recommendations, unless Porsche feels that the base stock in the 0-40 is different and superior to the other grades. Porsche does not include maintenance in the warranty, so it has nothing to gain by skimping on oil changes.

Interestingly, the regular CTS DI computer seems to be set for twice the oil life as the V, usually a minimum of 10,000 miles, or more. They still recommend no more than a year for the Mobil 1, though. Does any one know the recommendations for the base Corvette, which is basically the same engine as the LSA without the supercharger?

mik2718
10-04-09, 12:54 PM
Interestingly, the regular CTS DI computer seems to be set for twice the oil life as the V, usually a minimum of 10,000 miles, or more.

My '09 V OLM went from 99% to 62% over a recent distance of 4,934 miles. That was on Mobil 1, after a dealer oil change.

GM-4-LIFE
10-04-09, 01:13 PM
I did my first oil change at 1,908 miles and my oil life monitor is at 26% right now and I am at 8,200 miles. I have gone just over 6K miles and it dropped to 26%, so it isn't pre-set by the computer for a certain amount of miles.

It goes by how you drive the car.

The Corvette owner's manual says to go by the oil life monitor or 1 year without a set amount of miles. At least that is what it said in my 2005 C6 Corvette owner's manual.

SG

marktanner
10-04-09, 02:02 PM
Yes, the computer takes into account the way you drive the car. My V is at 50% oil life at 3500 miles. My '08 DI, driven the same way, had it's first oil change at 7500 miles at one year, and there was still 40% per the computer. That's more in line with most other manufacturers that use synthetic oil, like BMW. It appears to me that the oil life is dropping twice as fast as my other CTS, and I'm not driving it any harder. Just wondering if it's because it's supercharged.

Gary Wells
10-04-09, 02:33 PM
Yes, the computer takes into account the way you drive the car. My V is at 50% oil life at 3500 miles. My '08 DI, driven the same way, had it's first oil change at 7500 miles at one year, and there was still 40% per the computer. That's more in line with most other manufacturers that use synthetic oil, like BMW. It appears to me that the oil life is dropping twice as fast as my other CTS, and I'm not driving it any harder. Just wondering if it's because it's supercharged.
Mark:
Probably due to the supercharger, more heat and even though the car is low mileage by normal standards, could there be more blow-by than in a car with a normally aspirated motor. The reason that I think that ti is a possibility is my 25K mile '87 turbo Buick's Mobil1 is extremely dark at 3K mile intervals, even though I change the filter and the oil. This is my 5th '86-'87 turbo Buick, and they have all been that way.

s4ologist
10-04-09, 10:17 PM
I haven't been gutsy enough to wait until it indicated the oil needed to be changed. I changed the oil at 2500 miles, then, just recently at 9500, when the oil life was only down to 25%. It is amazing to me that I could basically go 9-10K miles between changes according the the on-board calculator. I am just going with the recommended Mobil 1 5W-30 so far.