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Question, i was thinking about this the other day.

the NBS and newer trucks have the smart computer that will tell you when you need to change the oil and do the reset on its life. Do you guys go by this on when to change the oil or do you stick to a XXXX mile oil change and reset the life after each one of those changes? just kinda curious
 

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Where's the van?!?!?!
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oil changes are cheap compared to the cost of a vehicle.

I do a synthetic oil change and tire rotation every 5,000 miles. Might be overkill, but its a wise investment IMO (and its easy to remember multiples of 5,000)
 

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thats what i was thinking. im switched over to 5K changes with synthetic and i planned to change it when i hit 5k miles, vs letting the truck tell me its time
 

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5,000 isn't unreasonable, but it may be wasteful. I've got 184,000 miles on my truck, it runs great, and I did NOT always obey the light. Once when it was relatively new I ignored when it said "engine oil low", figuring it had to be a bad oil level sensor, but I actually ran it dry for probably a couple weeks. I've usually changed the oil when it said to, but sometimes I've procrastinated for another 3,000 miles. I've taken it to a few different local shops, occasionally Jiffy Lube, and the last couple I've done myself.

I don't know anybody who has ever suffered consequences from their oil change habits, even if they were totally negligent. Who do you know who has followed the manufacturer's schedule and had a failure that could be blamed on not exceeding that schedule or not using better-than-specified products?
 

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I change my oil when it gets dirty, usually between 6,000 - 9,000 miles.

The computer isn't that smart, it just goes by engine revolutions over time and a few other variables. It's not like, "Hey, this is the exact time that would be perfect for you to change your oil so your truck never breaks down".

If I've been doing a lot of stop-and-go, I check my oil every 500 miles or so. If I've been on the interstate quite a bit, I check every 1,000-1,500 miles.

I do, however, rotate oil filters every 3,000 miles or so.
 

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i would go with mileage vs trucks comp.
once i went 6k miles before the comp told me to change oil, luckily i had changed it at 3
if truck has high miieage and you go with syn. its better to change every 3k
but if low miles i would do 5k with syn.
 

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I think that the oil change intervals are based on engine rpms for these trucks. correct me if im wrong. for me it usually ends up meaning an oil change every 4000 miles. I would never go over 5000 miles on an oil change, and use an ac delco filter.
 

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GM oil lights come on based on driving conditions measurable by existing sensors -- engine temperature, RPM, maybe IAT, TPS, etc.

I think I read somewhere that Chrysler's system measures the oil viscosity and such. IIRC, it uses electric conductivity of the oil to measure how much life remains.

From http://www.goodwrench.com/Services/OilChange.jsp
Most GM vehicles are now equipped with the GM Oil Life System. This system actually senses your vehicle's speed and engine temperature and can continuously monitor operating conditions. This helps determine when it's time to change the oil.

This system can actually monitor your personal driving habits and your area's climate condition to let you know precisely when to come in for a Goodwrench Oil Change.
What they don't say there, but do say in the manual, is that it can't account for stuff it can't measure -- for example, operation in dirty/dusty conditions. In those cases it is recommended to change the oil sooner. It also can't account for different oil than what is specified, so if your oil doesn't at least meet the specifications in your manual, change sooner than the light comes on...and if your oil is better, you won't know the best time to change it.

carguy6702, mine rarely tells me to change the oil before 6,000 miles have passed, and I don't change early. I've got 184,000 miles on it and it runs great. There's just no need, with modern engine and modern oils, to change every 3000 unless you drive in really bad conditions 100% of the time or you drive more like a jerk than everyone else.
 

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I don’t remember if I read it in the manual or heard it from a sales person but the oil life monitoring system is only accurate to a certain point. You can go off of it but you have to be in the right driving conditions at all times (which we know no one is) It has to be the perfect degree of weather outside and all kinds of stupid shit.

I change mine every 5,000 miles no matter what the case. I rotate my tires every other oil change.
 

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You can go off of it but you have to be in the right driving conditions at all times (which we know no one is) It has to be the perfect degree of weather outside and all kinds of stupid shit.
That's like the old "normal vs. severe service schedule" debate. They're not going to want to warranty trucks for 100,000 miles telling people to follow the computer if it's not designed for a reasonable definition of "normal".

I change mine every 5,000 miles no matter what the case. I rotate my tires every other oil change.
5,000 is at least reasonable. :thumbsup:
 

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patio furniture breaker
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i wait for the light. i do the same with my wifes car. why not use that fancy computer? GM spent alot of money to develop the system, so lets no let it go to waste.

ok, some of that was sacasm, but some was not.

i dont put alot of miles on my truck, so i go by the light. but when it gets over 3,000 i check the oil pretty often just to make sure its clean. the last 2 times i've gone about 5,000 miles or 10-12 months. the oil still looks clean even before i got it changed.
 

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5,000 is at least reasonable. :thumbsup:
Its synthetic, so I know its a good mileage to change at. Everytime I drain it I get a little plastic bottle and cut the top and let some of the oil drain into it so I can look at it and it still looks like brand new oil everytime.
 

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fyi

This is directly from a GM publication for Techs. Its a few years old but still current.

Oil Life Monitor --

How Does It Know?
How long will oil last in an engine? What reduces the oil’s effectiveness? When should it be changed?
Lubrication engineers perform a number of tests to answer these kinds of questions. Vehicles are operated under prescribed conditions, and periodically a sample of the oil is taken into the laboratory for analysis. When the condition of the oil is no longer satisfactory, the mileage is noted. From controlled testing like this, engineers in the past have determined two sets of mileage numbers, one number for normal driving and the other for severe conditions. Severe conditions can mean that the vehicle is driven hot (for example, pulling a trailer up a mountain) or is driven such that the oil never warms completely (for example, trips less than 5 or 10 miles in a winter climate). It is then up to the owner to decide whether their own driving is normal or severe and to change the oil accordingly. Now, science and technology have found a way of taking the guesswork out of the picture. GM is installing an oil life monitor in an increasing number of new vehicles. Using a simple indicator lamp or readout on the instrument panel, this system notifies the driver when to change the oil.

Here’s information on how an oil life monitor works.

Additives
Straight oil is not an ideal lubricant in an engine. A package of additives is needed to give the oil properties it does not naturally have or to enhance its natural properties. Some of the tasks accomplished by additives:
- viscosity modifiers, to keep the oil the proper thickness over a wide range of operating temperatures
- anti-oxidant, to keep the oil from thickening
- corrosion inhibitors, to protect engine components
- anti-wear
- anti-foam
- detergents, to suspend solid particles.

What Makes Oil "Wear Out?"

If you were to start out with a crankcase full of fresh, clean oil, and drove the vehicle for a period of time, eventually the oil would have to be changed. During this time, what can change fresh oil into "worn out" oil?
First, dilution. When gasoline is burned in the combustion chamber, the by-products include a lot of water. Some of this water can find its way into the crankcase through piston ring blow-by. If the engine is cold, and if combustion is not perfectly complete, a small amount of acid is formed. It, too, can blow-by into the oil. You don’t need to be a top-notch scientist to realize that water and acid aren’t good things to pump through the lubrication system of the engine. If an engine is run long enough for the engine oil to warm, the water
and acids will evaporate and not accumulate. But, during very short trips in cold weather, water and acids can enter the engine oil and cause the oil to "wear out." Second, the degradation of the oil and its additives. We mentioned earlier that a number of additives are put into oil to improve its performance. If these additives are degraded or decomposed, the oil is no longer capable of doing all of its jobs properly. Oil with
degraded additives can become thick and dark. Additives become degraded by exposure to extreme heat. There are two places a lot of heat can reach the oil. One is near the combustion chamber. Oil at the top piston ring is exposed to very high temperature. And some bearing surfaces can also put a lot of heat into the oil at high operating temperatures. So, degradation of additives from high temperature operation is the second factor that can cause oil to "wear out."

How Can Operating Conditions be Used to Predict Oil Life?

Using carefully controlled laboratory tests, it’s possible for lubrication engineers to measure how long it takes to dilute engine oil during cold operation. And it’s possible to measure how long it takes for high temperature
to degrade the additives. We usually think of measuring time in hours and minutes, but for an engine, the
amount of revolutions it has run is also a good measure. So for the purposes of oil life, time is measured in engine revolutions. Engineers like to talk in terms of models. A model is a way to describe something
mathematically. It’s possible to create an oil life model that very carefully matches the results of analyzing the oil in a laboratory. The oil life monitor, then, is based on a model. A computer chip in the Powertrain
Control Module is loaded with a certain number of engine revolution counts. The count for each engine/vehicle combination is determined by testing. As the engine runs, each revolution is subtracted from the remaining count in the oil life monitor. When the count reaches zero, the instrument panel light comes on. But, here’s the clever part. When the various input sensors detect that the engine is running under either cold or hot conditions, it subtracts extra counts (penalties) for each engine revolution. So, the conditions that cause the oil to "wear out" make the counter run down faster. When the oil is changed, it’s necessary to reset the oil life monitor and the countdown begins again.


NOTE: Synthetic oil resists "wearing out" better than mineral oil, so the oil life monitor
is set to account for this, but only on vehicles that are specified for synthetic oil from the
factory -- the Corvette, for instance. Using synthetic oil in other vehicles is certainly not
harmful, but the oil life monitor will continue to count down as though the engine contained
mineral oil.

- Shirley Schwartz contributed to this article
 

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As holycow did a good job of pointing out, the oil system is basically a calculator. Takes a lot of inputs and when it does reach a certain point, it activates a light. But, the thing with all statistics and calculations, they have no way of calculating unknow variables.

Many guys on here will tell you their favorite brand or type of oil. If it matters that much, would that not effect your oil change interval? Running rich, leaking coolant into the oil, having the oil level dropping due to leaking, changing your filter between oil changes, running a high or low side of the weight of oil, etc. are all things that system does not know.

IMO, it is just another idiot light. I keep an excel spreadsheet of everything I do to my vehicles,from wipers, trans service, tire rotation,etc. to oil changes. Input date and mileage. When it is time, I do it.
 

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My oil change notification wont turn off either that or the shops are dumb. It has been on for the past 15k which has had 3 oil changes. I dont really notice it anymore.
 

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My oil change notification wont turn off either that or the shops are dumb. It has been on for the past 15k which has had 3 oil changes. I dont really notice it anymore.
Have you checked to see if they are really changing your oil? haha
 

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My oil change notification wont turn off either that or the shops are dumb. It has been on for the past 15k which has had 3 oil changes. I dont really notice it anymore.
I dunno, you'd better go back to the shop. There's no way you could reset the light yourself. It's not something easy like you turn the key to the ACC position and press the gas pedal three times in 5 seconds.
 

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I dunno, you'd better go back to the shop. There's no way you could reset the light yourself. It's not something easy like you turn the key to the ACC position and press the gas pedal three times in 5 seconds.
Indeed, not like that at all. I mean, after all, why would a system that calculates oil life without using any kind of sensors need someone to tell it when the oil has been changed?
 
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