The oil life monitor only works on an algorithm, it does not actually "monitor" the oil. There's a base range and time, then km's are subtracted when you rev high, run cold, stop-and-go, and generally drive. This is displayed as a % life rating. I think it's crap, but all the manufacturers are going this road, and say it's law. Also, Delco filters are white in Canada.

I use the monitor and mileage as a combo. Usually at 6000 mi my monitor reads 20%. I'm using mobile 1 syn 15-50 and a K&N filter (longer size). Besides you need to rotate your tires about every 6,000 mi anyway, so why not do them both at the same time.

I have a 99 GT and change the oil around 10,000 and I have 160,000 on it and haven't had any problems yet

10k!!!! Damn now thats pushing it. Glad to see you got the life out of it. But now with the high mileage Id start to change the oil more frequently if I was you. There is a bit more slop in the motor now and any unburnt fuel could end up in the oil destroying the oil composition. With any luck you can get another 100k out of it.

I have been doing 4k-6k the past 20,000 just to be on the safe side , Thanks!

Same here. I use AMSOIL XL7500 synthetic with the AC Duraguard Gold filters; THE BEST! I change about every 4-5000; don't ever really check the life indicator, but from what I've researched, it's fairly accurate. But, it never hurts to change it before the car tells you to. The more often the changes, the better!

If you are talking about the UltraGaurd Gold filters, where can you buy them, besides the dealer? The dealer here charges like 11 bucks for them. I used to buy them at PepBoys for like 7 bucks, but they went under over here. So I use Mobil-1 filters now, because the dealer isn't very conveniently located for me.

I have seen information correlating the oil life monitor predicted oil live vs. actual oil samples. I can assure you that the oil life monitor is on the conservative side when compared with real oil samples, for all types of driving.

Hey, Brian. Actually the #47 UltraGuard Gold has been discontinued by AC, along with all the other AC Gold filters, except the 44 I believe, which is the Vette number. Eleven dollars is about right, but I'm afraid that this may be the only place you can get them soon, since AC no longer is stocked anywhere except for dealers and authorized retailers like myself. I'd say, if you can still buy the Golds somewhere, even the dealer, buy em up! There is still alot out there in stock at the AC warehouses and dealerships' suppliers, but they will run out soon. I bought the last 2 cases that my supplier had, and that's it. So get em while you can! Actually, Mobil 1 and AMSOIL filters are just as good if not better, from what I've learned. The AMSOIL actually filters down to about 1 micron. (Stock or el cheapo filters usually filter down to about 13-17, if that.) Good luck!

Why do you think it's crap? GM has been using the oil life system for over 10 years now. They have a huge liability to manage with warranty concerns and their reputation. You know they have studied and documented every single part that goes into the oil life algorithm to make sure it works well. The way it works is that when you reset the monitor you get a bank of engine revolutions and the countdown begins. The system counts every revolution and subtracts from the bank, then in addition to that it looks at the operating conditions of the engine(hot start, cold start, high rpm, coolant temp, how long the engine was run, etc.) to determine how fast or slow to subtract additional revolutions. I have never seen a starting number for the bank but my guess is upwards of a million revolutions. Personally I do rely on the monitor. Looking at the oil and trying to determine the condition is extremly subjective. They only way to really know what is going on is to get an oil analysis test done. I worked at one shop and some of the customers would ask me after I changed their oil, "so wha'd the oil look like? Pretty black huh?" exact words. I would just think to myself, of course it's black. Oil gets black within the first couple miles of driving. Only in extremly clean engines will it stay gold for a little while.

I would just change it every 3-4,000 miles religously. Then there's no question at all. No, you can't tell by looking at it to see if it's time. Just do it in intervals, and you know you'll be in good shape.

the best oil life monitor is the little stickers you put on your upper left side windshield or where ever you desire.now that's 100% accurate...

231GTP has it nailed. The stickers are always right, and you don't have to worry about how they work.

I do use my oil life monitor. When it hits 40%, I change the oil(about 6-7000 miles).
Jack