AZ28driver

Just curious...How many of you actually wait for the change oil to come on before you change your oil? Even though I run Mobil 1 I still change mine every 3,000 to 5,000 miles.

Patman

If you are using the change oil light in conjunction with Mobil 1, you are totally safe. If anything it could be a bit conservative, as Mobil 1 can last 10-15k easily under the right conditions.

IMO, changing Mobil 1 every 3k is a waste, you may as well use dino oil if you're doing it that often. It is nowhere near worn out even at double that interval in a good engine.

Andrew97Cobra

I run my Mobil 1 up to about 5500 miles in my daily driver. Coincidentally, that's when my oil change reminder usually tells me to change the oil.

I'm anxiously awaiting Patman's test results and if they look good, I may just run the Mobil 1 much longer, but I will probably change the filter at some point in the middle.

I also use Mobil 1 in my Cobra, but that car won't see an oil change for another year or two since I only drive it 2-3k miles a year.

CySevans

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Patman:
<strong>If you are using the change oil light in conjunction with Mobil 1, you are totally safe. If anything it could be a bit conservative, as Mobil 1 can last 10-15k easily under the right conditions.

IMO, changing Mobil 1 every 3k is a waste, you may as well use dino oil if you're doing it that often. It is nowhere near worn out even at double that interval in a good engine.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">The oil should last that long, but I doubt the filter would. Once the filter gets at full capacity, it doesn't filter the oil as efficiently, leaving all those contaminents free to roam throughout the engine. That's the reason for changing it.

I use Redline racing oil and K&N oil filters, but I still change it at least every 5K miles. Better to be safe than sorry.

<small>[ December 12, 2002, 10:00 AM: Message edited by: CySevans ]</small>

Patman

Filters last a lot longer than you think though, especially if you're running a good oil. With a good oil, you'll have low wear metals, so therefore it will take a very long time to fill up that oil filter. You can always change just the filter too, while leaving the rest of the oil behind. I'm running a K&N oil filter too, and with the large size of the one I run on the LT1, I figure it is easily good to 12k.

As Andrew my good friend eluded to, I'm running an extended interval test on both of my cars right now. I will take out a small sample every 3k to see how the oil is doing, and will not change it out until the analysis results show me that it's necessary. I'm running Schaeffer Supreme 10w30 blend in my Firebird for this test, and Royal Purple 5w30 in my wife's car (her testing won't begin until the second oil change with this oil though, the first interval with a new oil should never be pushed to the limits since the residual old oil will affect the additive package for extended drains)

My oil analysis results will also show that very little contamination gets into the oil on a good engine. With tight rings you get very little fuel in the oil, and with a good air filter you get very little silicon (dirt) Any acids in the oil are neutralized as long as the oil's Total Base Number remains at a decent level (above 4.0 is pretty safe)

<small>[ December 12, 2002, 10:40 AM: Message edited by: Patman ]</small>

Patman

I also forgot to add that I'm doing two more tests.

One is going to be in my sister's car, a 1999 Civic with the 106hp engine (same as my wife's, only hers is a 2000 Civic). In her car I'm now running M1 TriSynthetic, and will run it to 6k, then go with SuperSyn for 6k. After that, I will run SuperSyn for a second interval, but push it for about 12-15k. She does a lot of miles (she put on 1300 miles in the last 3 weeks since I last changed her oil!) so her results will come up a lot faster than my wife's (since my wife only drives 125-150mi per week)

The other test is in my mom's 94 Probe GT. She has 130k on it now, but since she has retired she only drives it about 6-7k per year, all short trips. I am about to change out her 10w30 Mobil 1 Trisynthetic, which has been in there for 10 months and 5k. I will be putting in SuperSyn, and will leave it in there for one full year, regardless of mileage. But like I said, since she doesn't do much driving, it will show the durability of Mobil 1 in handling the shorter trips and keeping the extra moisture in check. One benefit of her situation though is that her engine warms up very quickly, so a 5 mile trip in her car is a lot like a 10 mile trip in an f-body, since her oil temperature comes up so fast.

I expect zero problems out of any of these tests. And will have oil analysis results for all of them to show that what I'm doing is not foolish at all. Hopefully I will prove to others that the 3k oil change is a thing of the past.

AZ28driver

Thanks for the great info. By the way does anyone know what the oil change sensor is looking at to determine when to change the oil? In other words does it truely monitor the oil or does is monitor your driving habits and base the need to chage off of that or is it a combination of both?

Andrew97Cobra

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by AZ28driver:
<strong>Thanks for the great info. By the way does anyone know what the oil change sensor is looking at to determine when to change the oil? In other words does it truely monitor the oil or does is monitor your driving habits and base the need to chage off of that or is it a combination of both?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I think that it just monitors stuff like outside temperature, engine temperature, amount of miles driven, number of cold starts, engine speed, etc. I would love to see the code written for that sensor.

Andrew

Patman

I've got the PDF file at home which describes what the oil life monitor on GM cars uses, but it's basically just using a preset mileage, then it subtracts from there based on engine revolutions and engine temperature. So if you drive the car harder the light comes on sooner, and if you do a lot of cold starts I also believe it comes on sooner too.

Bosch is working on an oil sensor that actually does monitor the condition of the oil. I expect that will end up in some high end cars in the future. I'd love to retrofit one to my cars if it is possible (and not too costly)

<small>[ December 12, 2002, 11:33 AM: Message edited by: Patman ]</small>

Andrew97Cobra

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Patman:
<strong>I've got the PDF file at home which describes what the oil life monitor on GM cars uses, but it's basically just using a preset mileage, then it subtracts from there based on engine revolutions and engine temperature. So if you drive the car harder the light comes on sooner, and if you do a lot of cold starts I also believe it comes on sooner too.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">And you've been withholding this information from me? <img border="0" title="" alt="[Mad]" src="gr_images/icons/mad.gif" />

Wouldn't it also need to have an input from the VSS to calculate mileage driven? In my Olds, once the oil life gets down to less than 10%, the trip computer tells me that there are 500 miles left and it counts down to zero.

Andrew

tmgxray

The change oil light comes on after so many rotations of the crank, not by the quality of the oil. The light is just a reminder that your engine has gone so many rotation and should need the oil changed. That is why you are supposed to reset the engine oil light every time you change your oil.

hope that helps

Patman

Andrew, if I sent you all the various documents I have on oil I'd fill up your email box in no time! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

I believe it would have to have an input from the VSS in order to figure out the mileage driven. It is a step in the right direction, I think, because it helps to get people away from the 3k mentality. The oil % section of the trip computer on my 97 GTP would show about 30% oil life left even after I had gone 5000 miles.

Patman

I found the link to the PDF file I was talking about, on the GM oil life monitor:

http://theoildrop.server101.com/ubb/...c;f=4;t=000116

Andrew97Cobra

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Patman:
<strong>I found the link to the PDF file I was talking about, on the GM oil life monitor:

http://theoildrop.server101.com/ubb/...c;f=4;t=000116</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You better stop posting for a while and enjoy post number 3333! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

AZ28driver

wow..ask and you shall receive. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> Thanks for all the great info!

Patman

Also, here is more info from another source:

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">LAS VEGAS -- General Motors will equip nearly its entire North American lineup over the
next five years with a patented oil-life system, allowing drivers to potentially conserve nearly 40
million quarts of oil (37.8 million litres) annually.

The GM Oil-Life SystemTM already in use on some GM models, tells GM car and truck
owners when it's time to change their engine oil, eliminating many unnecessary changes that
waste oil, said Michael Grimaldi, a GM vice president and vehicle line executive for full-size
trucks. The first high-volume truck application of the monitoring system is on all-new 1999
Chevrolet Silverado and GMC Sierra full-size pickups - GM's best-selling models - featuring
the powerful Vortec family of engines.

Speaking at the 1998 Specialty Equipment Market Association (SEMA) Show, Grimaldi said,
" the initiative is part of GM's continuing program to provide owners with a more hassle-free
ownership experience and more environment-friendly vehicles."

Oil-life monitoring, which senses when the oil in a vehicle is nearing the end of its useful life, has
seen limited use the past few years, particularly on the Chevrolet Corvette, Cadillacs with the
award-winning Northstar engine, and certain other GM car models.

Over the next five years, the GM Oil-Life systemTM will be available on 90 percent of GM's
North American production volume, Grimaldi said. At that level of usage, GM calculates that
one year's production of new GM oil-life monitor-equipped vehicles, coupled with longer
change intervals, will allow the annual decrease in the amount of waste oil in the area of 40
million quarts (37.8 million litres) compared to the same fleet not equipped with the monitoring
system. The system also promises to create a net reduction in the amount of oil used and
reduce the amount of solid waste in the form of used oil filters.

The patented engine oil-life monitoring technology involves computerized monitoring of engine
revolutions, operating temperature and other factors to determine when a vehicle's oil should be
changed. Rather than depending on fixed oil change schedules that may not be suitable for all
situations, the monitoring system customizes oil change schedules based on a vehicle's engine
and transmission type and an individual's driving habits.

"Every driver operates with different driving styles and under different conditions," said
Grimaldi. "The GM Oil-Life SystemTM compensates for that, allowing a customized diagnosis
of each vehicle's oil change needs."

When the system senses that the oil in a vehicle is nearing the end of its useful life, it notifies the
driver that an oil change is needed with a "change oil" dashboard message that's displayed for
15 seconds when the engine is started. Once an oil change is completed, the oil-life monitoring
system can be reset to begin a new analysis cycle.

This method of determining oil change schedules is more precise than the traditional approach
of basing the cycle on the number of miles (or kilometres) driven -- typically 3,000 miles
(5,000 kilometres).

Starting with the 2000 model year on certain vehicles, GM will raise the maximum mileage
allowed between oil changes for oil-life monitor-equipped vehicles to between 10,000 and
15,000 miles (16,000 and 25,000 kilometres), depending on vehicle brand and engine. These
longer intervals between changes will be available to drivers who average longer trips under
optimal operating conditions, helping them avoid the inconvenience and expense of unnecessary
oil changes.

The benefits to drivers of vehicles equipped with the oil-life monitoring system are clear. For
those who neglect to change their oil on a regular basis, the system provides reminders that a
change is due. If they heed the reminder and follow through with an oil change, they'll protect
their engine from premature wear.

Customers who thought they needed to get their oil changed every 3,000 miles (5,000
kilometres) or so, might be able to go longer between changes. This will save them money,
time, and, perhaps more importantly, precious resources.

The rollout of the GM Oil-Life SystemTM is in keeping with the more than 100 "green" design
initiatives on the new Silverado and Sierra full-size pickups which are now reaching Chevrolet
and GMC dealerships. These include the 89 percent recyclability of the vehicles and the
replacement of lead solder in power and signal distribution areas with a new "spliceless" bussed
electrical system design, which eliminates the use -- and ultimate disposal -- of 18 tons of lead
per model year. Also, GM's new full-size pickup fleet has the highest fuel efficiency of any
full-size truck manufacturer with potential savings of 3.7 million barrels of oil, or more than 157
million gallons of gasoline, over the life of one model year's production.

"This oil-life monitor initiative is further evidence of GM's commitment to its environmental
principles," said Grimaldi, "specifically the company's dedication to helping restore and
preserve the environment." Grimaldi said GM recognizes that this initiative, over time, may
impact the sale of oil and oil filters -- by GM, GM dealers and other operators.

"However, given the customer and environmental benefits it has to offer, GM believes that the
GM brand, and ultimately GM dealers, will be strengthened by offering high-value customer
features and industry-leading initiatives like this one," he said.

Smart oil-life monitoring is one of a series of vehicle maintenance advances by GM over the
past few years that result in a lower-cost, more hassle-free ownership experience. Others
include 100,000-mile (166,000-kilometre) spark plugs, battery rundown protection, brake
wear sensors, "run flat" tires, "filled-for-life" automatic transmission fluid, 100,000-mile
(166,000-kilometre) serpentine belts, "lubed-for-life" chassis components, cooling systems with
coolant-loss mode technology and 150,000-mile (240,000-kilometre) coolant, OBDII
onboard diagnostics, and roadside assistance.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">

Patman

DOH! I didn't even see my odometer hit 3333 on here! <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

Oh well, at least I know that sometime tomorrow morning my odometer on my 95 Firebird will read 123,456.7 km! I plan on stopping to take a digital picture! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Andrew97Cobra

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Patman:
<strong>DOH! I didn't even see my odometer hit 3333 on here! <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

Oh well, at least I know that sometime tomorrow morning my odometer on my 95 Firebird will read 123,456.7 km! I plan on stopping to take a digital picture! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I just realized that I somehow missed the 12,345 mark on the Cobra earlier this year!