What are Oil Life Monitors Based Upon ?

[Bryanccfshr]

TRDUSA2002
Why?

Certainly hard driving has an impact on oil life. But towing a trailer or doing some hot laps is not going to end the usefellu life of the oil immediately. It will only impact it. The same as takeing half a dozen short trips less than 3 miles during a 6 month interval. It certainly degrades the oil faster but if it is taken in those short trips being the exceptoion and the rule being a 15 mile country road or highway trip then the impact is less.

In some cases driving hard is really good for the engine. If it is followed by a period of easy cruising any fuel that is loaded into the oil at WOT will be flashed off.

 

[beanoil]

Thread resurrection.....
I have a new interest in the GM OLM. My sis just bought an 04 Malibu Maxx (neat car BTW.. huge trunk, and half the roof is glass over the back seat, and then the sunroof over the driver). Anyhoo, the dealer simply said to follow the OLM, and change when indicated. I've been reading, and the general thought is that GM uses temp, time, RPM, and zinc depletion, etc., so it should be fairly accurate. The manual says that any oil that meets GM 6094. Castrol conventional meets the spec, is the general opinion that one could use a conventional oil, and follow the OLM "ALWAYS", and get good results, or should a more structured, 4-5k OCI mileage base be followed?

 

[XS650]

quote:

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Originally posted by beanoil:
Thread resurrection.....
I have a new interest in the GM OLM. My sis just bought an 04 Malibu Maxx (neat car BTW.. huge trunk, and half the roof is glass over the back seat, and then the sunroof over the driver). Anyhoo, the dealer simply said to follow the OLM, and change when indicated. I've been reading, and the general thought is that GM uses temp, time, RPM, and zinc depletion, etc., so it should be fairly accurate. The manual says that any oil that meets GM 6094. Castrol conventional meets the spec, is the general opinion that one could use a conventional oil, and follow the OLM "ALWAYS", and get good results, or should a more structured, 4-5k OCI mileage base be followed?

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The GM OLM does agood job of evaluating how your oil is being used/abused. Even if you don't agree with how long it tells you to use the oil, it's the best indication of how fast your oil is being depleted, short af an UOA.

I think the wisest way to use a good OLM is to run it to some percentage, maybe 50% and get a UOA, then based on that decide how far you want to run it next time. A friend has a C6 Corvette with OLM and about 9,000 miles on it. He told me the OLM is showing about 50% oil life left. His driving is open road driving, always at least 10 miles and he doesn't drive very hard. I see others on the Corvette Forum that drive hard and have had their OLM tell them to change at under 4,000 miles

The Corvette uses GM4718M oil (Such as Mobil 1) and Chevy also says change at 1 year if the monitor hasn't hit 100% yet.

My C6 has about 3700 miles on it, about a thousand miles on the oil. I plan to pull an oil sample with a pump at 6,000 oil miles and see what the UOA sez. Then decide what % to change at.

BTW, I don't believe the GM OLM does any type of oil analysis or measurement (zinc depletion, etc).