Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

How often should oil changes be done?

37K views 20 replies 17 participants last post by  jegnls01 
#1 ·
I have a 2006 TB with the 4.2 6-cylinder. I have read the book and followed the onstar links for information about oil life. The book does not specify an exact mileage, it states that the mileage varies based on operating conditions and that a light will illuminate when it should be changed.
The oil change light has not come on, but I am at 6000 miles and can't stand it anymore. I changed the oil today and reset the oil life indicator (I guess it worked; there is no confirmation on non-DIC trucks). The old oil was thick and very black, and by traditional methods it appeared to be overdue for an oil change.
What does everyone else do? Is this new to later TBs or is this common to all? If you have an older or high mileage TB, what are you doing and how is your truck running? Thanks

Lee
 
#2 ·
Our extended warranty make us change it every 3600 miles or 3 months, whichever comes first. We usually have about 65% oil life remaining according to the DIC
 
#5 ·
If you have a current Onstar subscription, you can go to their web site and sign up for "OnStar Vehicle Diagnostics" Once a month it will scan all the systems on your vehicle, and send you a report, including the percent of oil life left, and at what mileage your next oil change is due.
GM spent a lot of time/money designing the oil life system. It works really well. Remember the I6 holds 7 quarts of oil, therefore the oil doesn't "wear out" as fast. Some have gone as much as 10-11K before the light comes on - others as little as 3K. Mine usually comes on around 8K.
http://www.gm.com/company/gmability...es/news/simplified_maintenance_qa_040104.html
If it makes you sleep better at night, spend the extra $ and change the oil every 5K.
 
#6 ·
im one of the ones that gets about 9 to 12000 miles before lightcomes on.
I have an 03, I6, 3.73 gears. all stock, and I will hit 96,000 soon. still have the original plugs in there too.
I have never changed the oil at the 3000 mile mark. have changed at 6000 to 9000 on average.
I`m currently typing this from a 4 computer internet cafe in Guadalajara Mexico, I changed oil before we drove down here... just because I already had more thant 6000 miles on previous oil....
But on the trip down here with 3 adults, 1 german shepherd, luggage, gifts, ice cooler, roof rack back, I achieved an average of 19 MPG. with best of about 22 and low of 17 I think.
When its just 2 passengers and take long drives and I baby it.. I can safely say I can get 24 MPG.
My normal everyday traffic and roundtown I also safely get 18 to 19 MPG and that includes stop and go...
so 19 MPG with all cargo and passenger and large bag on roof was great.
I safely trust going 6000 or more between oil changes.
As stated also. the I6 has to wear down 7 quarts of oil.... not the typical 5 or 6.
My engine has plenty of power too.
 
#7 ·
I know this topic has been beat to death but I'm with you. If the oil looks dirty , it's dirty. While the oil itself does not break down as in years past, I do not believe in recirculating dirt throughout my engine and oil changes (under thirty dollars) are cheap insurance. I change mine every 3000 miles or so, but that's just my preference.
 
#8 ·
One thing to keep in mind relative to the stand-by 3000 mile mark, is that the mileage you get between oil changes is affeted by a number of things including (as stated) oil capacity. When I worked for Cummins Engine I learned that one of the things that was absolutely critical to over the road trucks is long maintanance intervals and in short, more oil capacity means more time between oil changes (pretty much on a 1 to 1 basis (doube capacity, double mileage)). That being said, since the 4.2L has a capacity of 7 qts. which is quite large compared to most light duty gasoline engines, don't be too surprised if your light doesn't come on when you might expect. Most light duty truck engines have around a 5 qt capactity so we have an extra 40% of oil on board. That translates to roughly to an extra 40% of miles between changes. So even if you usually change oil at 3000 miles in a 5 qt engine, 4200 miles would basically be the equivalent for a 7 qt engine. Now, since oils and engines have gotten better, many engine manufacturers are recommending longer oil change intervals so between that and the additional capacity, 6000 miles and still no light doesn't surprise me at all.

Of course, like 85vette said - if it looks dirty, it is. Personally, I change anywhere from 5-7K on my Envoy, but I'd never tell someone that they're changing oil too often. Despite all of the improvements, it is still cheap insurance. Just my $.02.
 
#9 ·
My method. I use the DIC trip odometer "B" for my oil change mileage. Then I reset my Engine Oil Life Remaining parameter.

At around 3,000 miles on the oil Im at about 70% oil life remaining. I check the oil, top off if necessary but I pay close attention to the color of the oil. With 7 quart capacity and a synthetic oil - 3,000 miles is a drop in the bucket for the I6.

At around 5,000 miles I change the oil out of principal. I can go more miles based on an oil analysis I had once by Blackstone Labs (about $20 and well worth it!). The oil analysis report indicated the oil additives and protectants were slightly less than 1/2 depleted. I could've easily gone 9,000 miles on synthetic oil according to the analysis!

I change the oil anywhere between 4,000-5,000 miles. Depending on how dark it gets. I have 93,000 miles. Its personal choice. If you use a quality synthetic oil and check it often you can get well over 5,000 miles out of the oil and probably closer to 9,000 miles. I encourage an oil analysis for you to determine the best mileage out of your oil. :)
 
#11 ·
Every 6500

I agree that u should never tell anyone how often to change oil. That said, it has been proven over and over, changing your oil every 3000 mi is a waste. Unless you drive in very dusty conditions or use very cheap oil/filter. Modern oil just does'nt break down that quick. There are many studies on the web that apply to this very fact! Remember, manufactures would not recommend longer intervals on a vehicle they have to cover under warranty if it meant engine damage they had to fix because of dirty oil.:yes:
 
#12 ·
Im like MichEnvoyBoy, except I use Trip A for oil change and Trip B for miles traveled on a tank of gas (reset every time I fill up).

My light has never come on, and I run Amsoil so I change my oil every 8-10K and usually have about 15-25% oil life left. I think Im at about 3500mi right now and 65% oil life. It costs me too much $$$ to do 3-5K changes with Amsoil at ~5 bucks a qt with a Amsoil filter at $11, its about $45 for an oil change. I use synthetic so Im not crawling under my TB all the time, plus in the winter I usually never have to change it.:D
 
#13 ·
Scarab- great minds think alike. I use trip A for gas trip and oil change on trip B :D

Tomorrow Im going to change my trans fluid/filter (again). I have a digital label maker and I put the mileage and date of those kinds of services (air filter change, trans fluid change, power steering fluid change, brakes) on the air filter cover. :crazy: I know, a little OCD, but it works! lol
 
#15 ·
:D I keep telling people that Ive had my Envoy over 2 years (thats the longest Ive ever owned a vehicle!) and thats a good sign that I might actually keep this one. Trying to take the absolute best care of it.
 
#18 ·
The oil companies love you for the 3,000 mile thing. I have done once a year (Amsoil) 12,000-15,000 miles for decades with no problems. I also use zMAX. Nothing takes the place of checking your oil though. In harder than normal use, I might change the filter and add a quart.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top