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- Sep 28, 2002
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Thank you for the very informative post on the GM OLM. Finally the inside scoop that could never be duplicated in an article.
I think what he was getting at is that they take a generic one-size-fits-all conventional as the LCD so that the oil monitor is always 'safe', and then they derate the oil monitor so that when it says 'zero life', it still has some saftey built in.quote:
Originally posted by Pablo:
Good post, thanks.
2) Doesn't the starting amount of ZDDP effect the algorithm? Or is the calculation based on a fairly low concentration for a safety margin?
Wow, do you mean that mixing a quart of Mobil 1, with some GC, and some Havoline is not better?quote:
Originally posted by bbobynski:
My same comment applies....how do those darned Powertrain engineers manage to design/develop/validate an engine like the Corvette LS6 and not know the proper oil viscosity for it....LOL LOL Use the recommended viscosity. That is what the engine runs all validatin and endurance testing with. If you use something else YOU are doing the testing.
I bought a new Cadillac last July and after about 2 1/2 months got a letter from the dealer saying I need to bring it in for 3,000 mile service. The OLM was showing over 60% remaining life with close to 3,000 miles on the odometer. Anyway, I decided it wouldn't hurt to have the oil changed post break-in to be safe. Of course, the dealer put a window sticker reminder on to bring it in after another 3 months or 3,000 miles. It has now been close to 6 months and I've gotten a letter from the dealer that I'm overdue for serivce, and this week got a letter from GM that I'm overdue for my 9,000 mile service (7,000 on odometer). Of course, I know they are estimating milage, but I'm disappointed how hard they are pushing to ignore the OLM.quote:
Originally posted by Mike:
Educating the customer is hard but so is educating the dealer. ....
Boy, isn't that the TRUTH. Back in '96 when I purchased a Cadillac STS I knew far more about the vehicle and it's options than did the salesperson, and he was one of the rare salespeople who had been with the same dealer selling Cadillacs for over 10 years.quote:
Educating the customer is hard but so is educating the dealer.
Don't know. How did they manage to design/develop/validate the intakes and intake gaskets on most V6 and vortec V8's that have been leaking coolant internally for 10yrs?quote:
Originally posted by bbobynski:
...My same comment applies....how do those darned Powertrain engineers manage to design/develop/validate an engine like the Corvette LS6 and not know the proper oil viscosity for it....LOL LOL Use the recommended viscosity. That is what the engine runs all validatin and endurance testing with. If you use something else YOU are doing the testing.
quote:
Originally posted by Jason Troxell:
Don't know. How did they manage to design/develop/validate the intakes and intake gaskets on most V6 and vortec V8's that have been leaking coolant internally for 10yrs?quote:
Originally posted by bbobynski:
...My same comment applies....how do those darned Powertrain engineers manage to design/develop/validate an engine like the Corvette LS6 and not know the proper oil viscosity for it....LOL LOL Use the recommended viscosity. That is what the engine runs all validatin and endurance testing with. If you use something else YOU are doing the testing.
The "real deal" GM oil life monitor works as I have described it in the post above.....that is the way it has always worked since it's inception in the early 80's and first application in production in the 1986 model year. There has never been any sort of oil life monitor that is simply a mileage counter on a GM car so your wife is wrong....good luck convencing her, though...LOL.... The oil life monitor field validation work actually was done on Cadillac 4.5 and 4.9 engines back in the mid-80's when the algorithm was being validated and fine tuned for production. There was extensive testing of the oil life algorithm (working as I described in the treatise above...) on the Northstar engine before it ever went into production and I can assure you, positively, that the oil life monitor in a 94 STS is NOT a simple mileage counter and that it works exactly as I have described it...I know this personally for a fact...so you can show this to your wife...LOL.quote:
Originally posted by haley10:
bbob, my wife 1994 STS has an OLM, but she thinks it's just a simple 3K counter with possibly a time limit. Is this true? When did the real deal OLM come into being? Or is she simply wrong? 7.5 qt. sump and easy enough driving, I tend to believe her.
The designers are working under constraints that the owner may not care so much about. They have fuel economy targets, noise levels and other items that could be less important to the owner and therefore, a change in viscosity could be warranted.quote:
Originally posted by bbobynski:...My same comment applies....how do those darned Powertrain engineers manage to design/develop/validate an engine like the Corvette LS6 and not know the proper oil viscosity for it....LOL LOL Use the recommended viscosity. That is what the engine runs all validatin and endurance testing with. If you use something else YOU are doing the testing.
Is this contrary to Patman's theory that GC 0W-30 is the best oil for the vette' in terms of absolute wear #'s? And the M1 0W-40 is better theory?quote:
Originally posted by buster:
Do you have any info on how GM tested Mobil 1 in the Corvette? I read somwhere that they ran the car around a track and very high speed until the gas tank was low. They then tore down the engine and mearured wear. Also, what are your thoughts on oil analysis and engine wear? Is that something GM does when evaluating an oil?quote:
Current engines need very little of the anti-wear compounds to survive due to the extensive use of rolling elements at friction points, elimination of distributor drive gears for oil pumps, gerotor oil pumps, etc....
I run 5W30 in my 02 Corvette if that makes any difference to you..... The engines are rigorously tested with the viscosity grades recommended. 5W30 is fine.
I do agree with you in that many engines today don't need high levels of anti-wear additives. Another area where BITOG UOA's show this. Toyota must really be doing something right.
No, I was making a point. If the logic that the factory knows best for oil viscosity is true, it could be true in other cases. That is not putting words in your mouth, as I did not indicate that those were your feelings.quote:
Originally posted by bbobynski:
You are also putting words in my mouth by "extending" my logic for me. Please refrain from doing this as you do not understand my logic apparently at all.
What about the case of technological advances? Car comes from the factory filled with 10w-30 and that is what recommended, but technology allows a 0w-30 to do all the 10w-30 ever did and more. Then what? Is the factory still right?quote:
Originally posted by bbobynski:
Snip...The OEM recommendations for the unit as delivered are the best and correct for what the vehicle was intended for and certified for. Period. Follow them for best results.
It appears to me that both of you are in agreement, so it escapes me as to why the continued posting. You are happy in doing your own "testing", and he is happy that you are happy in doing your own testing.......quote:
You presume that the factory always has in mind EXACTLY the same goals as the owner. This is simply wrong. You are correct that it is always a good choice and more often than not, it is easier to make a mistake by changing than it is to make an improvement. However, to imply that the factory recommendation is always the best for an unmodified vehicle, seems to me to be a little pretentious when coming from a factory engineer. There is a chance that an owner could want something different from their car (and oil) than the multitude of constraints that were placed upon engineers at the time of development.
yep, just ran it around the track a time or two and called it good.....LOL LOL LOL ..... I think you have the aftermarket mixed up with the OEM's. That is how they do it....quote:
Originally posted by buster:
Do you have any info on how GM tested Mobil 1 in the Corvette? I read somwhere that they ran the car around a track and very high speed until the gas tank was low. They then tore down the engine and mearured wear. Also, what are your thoughts on oil analysis and engine wear? Is that something GM does when evaluating an oil?quote:
Current engines need very little of the anti-wear compounds to survive due to the extensive use of rolling elements at friction points, elimination of distributor drive gears for oil pumps, gerotor oil pumps, etc....
I run 5W30 in my 02 Corvette if that makes any difference to you..... The engines are rigorously tested with the viscosity grades recommended. 5W30 is fine.
I do agree with you in that many engines today don't need high levels of anti-wear additives. Another area where BITOG UOA's show this. Toyota must really be doing something right.
Just to confirm, GM is NOT changing from DexCool or to another formulation of coolant or anything. DexCool is the factory fill coolant and will be for the forseeable future. There are no plans nor development program to change from DexCool. None. Period...rumors to the contrary are simply....rumors...with no truth in them.quote:
Originally posted by Mulaka:
Supposed to change to something called Zerex G-05 starting in 2006.