I purchased a 2006 Buick Lacrosse back in October. I have driven it about 3,000 miles. This car is equiped with the GM Oil Life System. According to the owners manual it is no longer necessary to change the oil every 3,000 miles. Just do it whenever the “Change Oil Soon” message come on the display. I have asked a few mechanics and dealers. Some say trust you should do what the owners manual says. It will cause no problem. Others have said No you should still do it every 3,000. What should I do?
Do what feels best to you.
Basically 3000 miles(now 5000 miles) is a conservative number that used to average most drivers conditions together. Some it was just in time(short trips in the city) others could even go twice that distance safely.
However the GM oil life monitor is basing your oil change interval instead on how you drive the car and how far etc based on the computer management.
I second Andrew’s suggestion.
It’s important to realize that the system is not performing any analysis of the oil, just running mileage and type of driving through a computer program.
It’s also important to realize that oil cannot be too fresh, only too old. If you prefer to change it every 3,000 miles that’s a good thing.
I still change at 3000 but agree there should be no problem going to 5000 which would still be very conservative. At 3000 usually our oil monitor shows 50% used up. On a late model like this I’d be inclined to change when it hits 50 or 40% oil life remaining or 5000 whichever comes first. Can’t really go wrong with that. No way am I ever going to 7000 or 10,000 regardless of what the computer or manual says. Some of this is just marketing to reduce maintenance requirements. Only exception would be the first oil change for break-in period. IMHO anyway.
Some years ago I read a paper by 2 GM engineers on the results of ongoing acidity measurements of crankcase oil to determine the proper drainage interval. This point would coincide with the approximate additive depletion point. The results were quite startling; for stop & go driving, with litle engine warmup, the oil change interval (with some safety margin) was 3500 miles. With cross country highway driving at legal speed limits, about 8000 miles was achieved, with the same close to 100% margin, all using off the shelf standard oil.
However, implementing a proper and reliable oil sensing sytem cost a lot more than programming the car’s computer, so GM chose the cheap way out once more.
Personally, I would trust the book more than the computer; however, there are those who need to be reminded by red lights flashing that their cars need service.
Docnick, The GM oil change countdown system as I understand it counts engine revolutions and cold starts for more than hot starts. Their system accurately emulates the deterioration of oil. Do you know of any vehicle maker who actually uses an onboard oil chemistry analysis system?
To state that GM used the cheap way is a negative statement for two reasons as follows:
- I doubt that you would want to pay for an onboard oil chemical analysis apparatus when a cheaper way is entirely satisfactory. Engineers get paid do that all day long, to find a cheaper solution to a problem or a need so that you and I can afford it.
- Not too long ago, there was no oil change countdown timer available in low priced cars and further back, in any car at all. That is an improvement that should be appreciated, not criticized.
Thanks for your comments; yes I am aware of the simulation programmed into the computer.
Ongoing oil analysis is now practiced on large industrial machines like marine diesels and some locomotives. The acidity measurement is not all that complex, but needs to be robust.
BMW has a complex analog system to tell the driver when to change oil. The European union is trying to cut back on waste oil generation, so most cars there now have very long drain intervals, and using the analog to stretch that out will be good for the environment. My requirement would be input of ambient temperature, since warmup from -10F takes much longer than from 60F.
However, all in all I agree with you that the computer simulation is a useful add-on to the engine monitoring system.
Actually its pretty easy for an engine to understand ambient temperature. It knows the duration of how long it takes for the coolant to warm up and the operating parms associated with. This I believe is taking into consideration of the oil life monitors.
I have this same GM oil life system on a 2006 Uplander. When I do town driving with short distances, the “Change Oil Soon” message appears in about 3500 miles. In the summertime when I had it on a long trip, I didn’t get this message until about 7000 miles. I trust the system as short distances are harder on the oil than long distances. I always did this same thing on my cars without this feature–my formula iis long trips = long oil life while short trips = short oil life.
I don’t think that the GM Oil Life System adapts itself to different types of oil, but is probably calibrated for the type of oil recommended in the owner’s manual. In other words, the system may suggest an oil change too soon if one uses synthetic oil. However, I use the type of oil specified in the manual.
This system is different than the one on our 2003 Toyota 4Runner. A mainenance light comes on at 7500 miles to tell us that it is time to change oil. I don’t use this system. If our drivng has been mostly town driving, I change the oil around 4000 miles. I may stretch it to 6000 miles if we have done a lot of highway driving. When I have had the oil changed, the mechanic often forgets to reset this light and I’ve had it come on when I’ve changed the oil less than 1000 miles earlier. If I have to have a system on a car, I much prefer the GM Oil Life System. However, I could do without either system. I think I have enough good sense to realize what kind of driving I’ve been doing and change the oil accordingly.
When in doubt, change it. I like newer cars because I can keep the hood closed. If I don’t change it at 3,000 miles, it may never get checked. I’ve checked it twice since September. I have a check oil soon light too which tells if it is down to a little less than five quarts. The system takes about 6 quarts in my 4.8. When the check it light came on because I only put five quarts in it the first oil change, I added half a quart and changed the oil a few weeks later because it was 3,000 miles. If you divide the cost of your car by the price of an oil change, you will see how many oil changes you can get before you equal the price of the car. It may come out to be 833. Multiply that by 3000 and you get 2,499,000 miles before you spend the price of the car on oil changes. We should all live so long. Assuming your car cost 26,000 new, and an oil change is $30.