Corvettes OLM changed in 2001 (increased 50%)

[Corvette Owner]

FYI, 1997-2000 Corvettes used 10,000 miles as the maximum oil change interval (OCI) for the Oil Life Monitor (OLM), the "subtractions" based on oil temperature and total rpms would start with 10,000 miles.

In 2001, GM increased the maximum OCI on Corvettes to 15,000 miles maximum, based on extensive used oil analysis performed. So, evidenntly they found out that Mobil 1 synthetic oil was "better" than they originally thought.

This means that for 1997-2000 Corvettes, you can run your car down to 50% oil life left, then reset and run down to 0%. Or you could go to 0%, reset and go to 50%.

I have a 1998, and I change at 0% anyway, it is equavalent to changing at 66% on a later year Corvette.

 

[jorton]

Does your 98 have the same motor oil capacity as a 2001/later year model has?

 

[VK56VD]

If I had a Corvette and drove it hard, I would change my oil sooner than 15k or even 10k miles if Mobil 1 were used.

 

[Art_Vandelay]

Did all 2001+ GM cars undergo a similar 50% OLM stretch?

Is everything under the hood the same to allow you to rule out the engine mechanics as the reason for the extended maximum?

Just because one counts down from 15,000 and the other from 10,000 doesn't mean that the 50% difference is maintained throughout the interval.

- For all you know the 15,000 mile OLM might indicate a change sooner than the old one based on more aggressive calculations.

Don't trust that assumption.

 

[Corvette Owner]

All C5 Corvettes (1997-2004) have the same 6.5 quart oil capacity. They have a big oil pan with "batwings" on the bottom. They had a problem with oil starvation because of the high g cornering ability during C5 development and the pan was their way of solving it (there is also an electronic limit if you use a skid pad for too long, it cuts power to the engine).

Interesting enough, the C6 (2005-?) Corvette uses only 5.5 quarts of oil with a new design oil pan. They do have larger oil capacities with some options, including an 8 quart dry sump system.

We had a GM Corvette Engineer on Corvette Forum who detailed this change in OLM for us, the software is the same, only the limit was raised.

I don't know if ALL GM cars underwent this increase, I doubt it since Corvettes use Synthetic Oil, their OLM is calibrated for this. Now, maybe the Cadillac CTS-V (uses a corvette engine) did ? Years ago, when the Camaro used a Corvette engine (LS1), it did not use synthetic oil fill (from the factory). It was because of the heat produced by the smaller space in the Corvette, GM didn't want to install an oil cooler, so they specified synthetic oil to save money.

As I said, I still change oil at 0% on my 1998, which is 66% of the new limit. I do used oil analysis to verify and they always indicate I have several thousands of miles left in the oil. With my driving, the OLM comes on at 5,700 to 6,500 miles.

I use Mobil 1 in my other cars and change at 7,500 miles. My daughter's OLM in her 2009 Chevy Malibu has indicated OCIs of up to 9,000 miles (she does a lot of highway driving) and that is for conventional oil ! I have no doubt that a good Synthetic Oil will last 10,000 miles in most cars, I know a lot of people here do that with no problems.

 

[tig1]

Even though the Mobil 1 5w30 Extended Performance doesn't have the Vette spec on the bottle it is still good to for the Vettes. Per Mobil tech. May want to try it. Just a thought.

 

[Corvette Owner]

Originally Posted By: tig1
Even though the Mobil 1 5w30 Extended Performance doesn't have the Vette spec on the bottle it is still good to for the Vettes. Per Mobil tech. May want to try it. Just a thought.


I have emailed Mobil 1 and they said that their EP DOES MEET the Vette Spec, although it is not on GM's list or the bottle???

In an older post, I detailed that I have switched my Corvette to Castrol Edge due to some wear (lead) I have seen in recent (last 3 years) used oil analysis with Mobil 1. I am half way through that OCI and will post results here when I get them.