Seriously, when to change oil?

[PnCRedJwl2SS]

Originally Posted by JOHNREX

At what percentage OIL life indicator should you change the oil at 50%, 40%, or 20%?

I would not go much below 20% on the DIC.

[jehartley]

Originally Posted by JOHNREX

At what percentage OIL life indicator should you change the oil at 50%, 40%, or 20%?

Have your oil ready and when it gets to 5% change it.

[joeaux]

God. Just read the manual page 10-2. Why is the considered voodoo? Everyone seems to have a goofy opinion on it. Just do what GM recommends. Change the oil WHEN THE CAR TELLS YOU TO or once a year (oh and that's also on page 10-2). Now that was easy wasn't it?
-joe-

[Ject]

Originally Posted by joeaux

God. Just read the manual page 10-2. Why is the considered voodoo? Everyone seems to have a goofy opinion on it. Just do what GM recommends. Change the oil WHEN THE CAR TELLS YOU TO or once a year (oh and that's also on page 10-2). Now that was easy wasn't it?
-joe-

Could you go over that in greater detail plz?

[mulletman]

Don't trust the oil life monitor! It's a DIC!

[2SSARMY]

I'm going in for the 4th oil change tomorrow, and I am at 12,500mi.

[nova]

I did mine at 1000 miles and was glad I did. To only have a 1000 miles on the engine and oil it was pretty funky.

My view on the GM recommendation vs earlier changes is this. GM has to strike a balance between engine wear/warranty issues and maintenance costs for the buyer. Changing the oil more is certainly not going to hurt the engine, only your wallet. No engine ever had issues because the oil was too fresh :p

[MadMav]

I ended up changing it at 2850 miles with Royal Purple. It was pretty clean when it came out. So it was happy. I now have 6K and will probably go another 3k before the second change. Depends on how much racing I will do this year.

Mav

[baysinger]

Changed oil at 1500 mi. I also changed my diff. this past Saturday at 2000 mi. The diff fluid that came out looked like crap. A lot of metal on the fill and drain plugs. I went back with RP 75W90 SYNTHETIC with the LS additive already in it.

[Jarhead]

Originally Posted by Doc

I changed mine at 60 miles, 600 miles, and 1,700 miles. Here's why:

The greatest amount of particles that are going to be found in the engine happen in the first 50 miles due to whatever "stuff" might have been left in the engine during assembly and the high amount of wear-in/ring seating that takes place at that time. The cylinder walls are cross-hatched honed to make them function like a file so the rings will literally wear themselves down against that surface which also wears down to "seat" or seal the rings against the cylinder walls.

All the leftovers from assembly plus the particles worn off the rings are in your oil. The filter catches most of it but any silicone or items from assembly will also get in there and have the possibility of clogging the filter which goes into bypass mode allowing the oil to circulate as-is. Whatever metal particles are in your oil are splashing over all the moving components. Replacing the oil and filter in the first 50 miles or so clears all that out and gives you a clean filter to catch the next wave which happens in the first 500 miles or so. I switched to non-synthetic at 60 miles because synthetic does too good a job at protecting the cylinder walls and I wanted mine to seat correctly.

I changed it with non-synthetic again at 600 miles for the same reasons as above; to remove the wear-in particles from breaking it in. At 1,700 miles I changed it again except this time I put synthetic; I used Royal Purple because it's my preference but you'll always find the Amsoil distributer chiming in whenever you mention RP and the guys who righteously post about how "the owner's manual says..." and how they've never had a problem in 50 years of driving. That's fine; use whatever oil you prefer. Mobil 1 is great stuff, I just prefer Royal Purple.

I also changed the transmission and differential fluids at the 1,700 mile mark. Same reasons; clearing out stuff left over from the assembly line and initial wear-in. When you see what the fluid looks like as you drain it; especially the differential, you'll be glad you changed it. Once again I used Royal Purple fluids because I've had great results with their products for years; use whatever you prefer.

My car now runs smoothly and quietly and just glides along compared to when it was brand new. The main value in doing changes like these outlined above is to remove the bulk of the wear-in material and whatever might have been left over from assembly. I spent less than $100 on the first 2 changes which to me is no big deal when taking care of a $35,000 car. I spent less than $200 on the 3rd change which included engine, filter, trans and diff plus labor. Again no biggie to me considering what I'm protecting. My car is now set for it's life and I plan on keeping this one.

Best post I've read in quite a while.

[wirebender]

Originally Posted by joeaux

God. Just read the manual page 10-2. Why is the considered voodoo? Everyone seems to have a goofy opinion on it. Just do what GM recommends. Change the oil WHEN THE CAR TELLS YOU TO or once a year (oh and that's also on page 10-2). Now that was easy wasn't it?
-joe-

It (the manual) also says that IF you accidentally reset your oil life indicator to change the oil at 3000 miles from the last oil change!!!! I'm changing mine every 3000 (or fairly close to it!)! Thats not vague nor does it rely on how accurate a monitor is....and if the oil life monitor is as accurate as the tire pressure monitor......I'll stick with the odo and change every 3000!!! lol

[joeaux]

LOL. I love this. Everyone just makes up their own idea of what's best. Funny stuff.
-joe-

[DGthe3]

Originally Posted by joeaux

LOL. I love this. Everyone just makes up their own idea of what's best. Funny stuff.
-joe-

Well, if we're just making stuff up ...

Change your oil any time you think about it. Its probably been a while

[joeaux]

Heh. I'll change it when the car tells me too. Sheesh.