: Oil change today after 12,735 since last oil change

09-15-06, 07:36 PM
It's been five months and one week (April 5) since my last oil change for my 2003 STS.

With "1%" showing on the Oil Life Monitor, the oil was changed today.

Two quarts were added since last oil change: 1 qt 5W-30 dinosaur oil, 1 qt 5W30 Mobil 1. This means it uses one quart every 6,300 miles.

Last oil change: 6 qts Mobil 1 5W-30, 1qt Mobil 1 10W-30

This oil change was 7 qts Mobil 1 5W-30.

Total miles since last oil change: 12,735

I thought the OLM maxed out at 12,500 miles, but this proves otherwise.

09-15-06, 07:41 PM
Since you were at 1% I suspect the 12,500 cap was when you got the change oil message at 10% (which was likely at 12,500).

09-15-06, 07:44 PM
I never got the 'Change Oil' Message.

I shoulda waited until it hit 0%. I was wondering when the message would show.

09-15-06, 07:46 PM
The last writeup on the OLM that I saw said that the max is a reading of 0% plus two tanks of fuel so youstill had some margin.

09-15-06, 10:23 PM
Ah...makes sense. But the new questions are, When does the "Change Oil" message first appear" and "How many times does it remind you?"

09-15-06, 10:31 PM
I have always been of the understanding (and it has been my expirience) that it comes on at 10% remaining and stays on or returns at each start up till reset.

09-16-06, 10:24 AM
That's what happens in my car to. I've got to hit the info button to clear it from the dash, but as soon as I cycle the key it comes back on.

El Dobro
09-16-06, 10:44 AM
The monitor used to give you a couple of different warnings when I had my '91 Seville. I could be wrong, since it's been awhile, but I believe it started at 10%, had a different warning at 5% and a new one at 0%. On the '98, it comes on when you have only a couple of hundred miles left in the life of the oil.

09-16-06, 08:24 PM
All this talk about "margins" and oil "life" remind me of what the Guru once said. He said that there was about a 100% saftey margin built in. Meaning that with todays oils you could actually reset the OLM and run it to 0% again. He converted me from the 3k oil changes, but I have to admit 25K would take a LOT of converting.

09-16-06, 08:55 PM
Today's oils and engines are amazing. I have gone from changing oil every 3000 miles (years ago) to almost 13,000 miles. That's four times fewer changes. It's to the point where oil changes are a minor expense. In many cases, it costs less than a tank of gas!

09-16-06, 10:03 PM
The "change oil" message has changed quite a bit over the years. Not all models are the same. The earlier cars with the oil life monitor would put the message "change oil soon" at about 10% and then "change oil now" at 0%. All the GM cars have gone to a standardized "change oil" message at the next key on event after the oil life is at zero percent. There is still plenty of safety factor in the oil change interval in terms of actual oil life left but it is not as great of a margin as is was a decade ago. Part of the increase in the allowable oil life over the years is due to engine changes and part of it is due to the improved oils. Just because newer model cars can go further on oil change intervals does not mean that older cars with shorter oil life intervals calibrated into the oil life monitor should adopt the newer intervals. The older engine designs would still require more frequent oil changes per the oil life monitor calibrated into those vehicles.

12,700 miles for the oil life monitor would be indicative of driving under optimum conditions...i.e..long trips, highway miles mostly, summer time driving and no really cold cold starts, etc.

09-17-06, 05:18 PM
12,700 miles for the oil life monitor would be indicative of driving under optimum conditions...i.e..long trips, highway miles mostly, summer time driving and no really cold cold starts, etc.
Yes, that is correct. The car gets about 90% highway miles. Start it up, drive 45 miles. Do that twice a day. When roads are sloppy with snow, sand, and rocks, I take the old 4x4.

09-20-06, 09:58 PM
Here, I'll save you $20. Used oil analysis of an '04 DeVille, 11,200 miles on Mobil 1, OLM down to 7%.

Click Here (http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=003068#000000)

09-21-06, 03:42 AM
Interesting.I have 1500 miles from next oil change but OLM says %50.I am using Castrol 5W30 .Maximum oil life is 6250 miles at the product .