Can GM's OLM be used for other vehicles?

[RamFan]

This is something that just recently popped into my head and wonder what you guys think.

If you've got two or more vehicles, one a GM, the rest something that does not come equipped with some kind of OLM system. If all the vehicles are driven in equal conditions, could the GM OLM system be used to figure out a good OCI for the other vehicles?

I know this will not work for all engines; Chrsyler 2.7l (-2002YR), Chrysler 4.7l, Nissan's VQ series, and late 90s Toyota engines come to mind. But for your average non-high performance, non-sludge prone engine could this work?

 

[The motor guy]

I don't see why not. Unless it's like you said and is a sludge prone engine. Like some toyota engines. I suppose if I had a sludge prone engine I would stick to 3000 mile oci.

 

[The Critic]

Different engines degrade oils at different rates, so no. Not every engine runs at the same temperature, puts out the same amount of fuel dilution, has the same sump size, etc.

 

[Hokiefyd]

No, it cannot. Even in GM's own powertrain portfolio, different engines have different OLM algorithms. For instance, the 1st and 2nd generation Northstar engines had different "maximums" set in the OLM because one had roller cam followers and the other design had direct-acting buckets. I believe the percentage "accrual rate" was also changed accordingly.

So no, I don't think you could project one vehicle's OCI recommendation via OLM onto another vehicle.

 

[RamFan]

Originally Posted By: Hokiefyd
No, it cannot. Even in GM's own powertrain portfolio, different engines have different OLM algorithms. For instance, the 1st and 2nd generation Northstar engines had different "maximums" set in the OLM because one had roller cam followers and the other design had direct-acting buckets. I believe the percentage "accrual rate" was also changed accordingly.

So no, I don't think you could project one vehicle's OCI recommendation via OLM onto another vehicle.


I was not aware that the algorithms were different, I was under the assumption that they had one algorithm for conventional, one for synthetic, and one for DI. Thanks for the info!

 

[440Magnum]

Originally Posted By: RamFan

I know this will not work for all engines; Chrsyler 2.7l (-2002YR), Chrysler 4.7l, Nissan's VQ series, and late 90s Toyota engines come to mind. But for your average non-high performance, non-sludge prone engine could this work?


It would probably be an OK guide... but then so would just doing a periodic oil analysis for the first run or two and getting a feel for what the engine does to its oil that way. In fact I think that would be better.

And to pick nits- the 4.7 sure as heck shouldn't be on any "sludge prone" list. The 2.7- definitely, but not the 4.7.

 

[RamFan]

Originally Posted By: 440Magnum
Originally Posted By: RamFan

I know this will not work for all engines; Chrsyler 2.7l (-2002YR), Chrysler 4.7l, Nissan's VQ series, and late 90s Toyota engines come to mind. But for your average non-high performance, non-sludge prone engine could this work?


It would probably be an OK guide... but then so would just doing a periodic oil analysis for the first run or two and getting a feel for what the engine does to its oil that way. In fact I think that would be better.

And to pick nits- the 4.7 sure as heck shouldn't be on any "sludge prone" list. The 2.7- definitely, but not the 4.7.



I think you and I have argued about whether or not the 4.7l is also sludge prone before, and we didn't agree then so I doubt we will agree now lol.

 

[Gene K]

Take the highway mpg rating and prorate it to the maximum oil change interval. Then adjust based on actual average mpg and then adjust for the oil used.

My truck...
18 mpg EPA Highway.
Max OCI - 6,000 Miles

6,000 / 18 = 333.33

Actual average - 19.3 MPG

19.3 x 333.33 = 6433.27 miles

6500 Miles = Conventional

6500 Miles x 1.5 = 9750 Miles Synthetic

6500 Miles x 2.0 = 13000 Miles Extended Drain Synthetic