TEXHAWK0

I used to change my oil every 3,000 miles, but started going by the oil life monitor. I last changed my oil at 1% oil life, and 4,500 miles. When I changed the oil, I caught a sample and had it anaylzed. The analysis showed no unusual signs of wear, <0.5% fuel, 0.0 % water, and a TBN of 5.7, compared to a TBN of about 12 for new Mobil 1 oil.
The TBN (Total Base Number) is a measure of the amount of additives still left in the oil. From these results it appears that even the oil life monitor is conservative for normal, everyday driving.

One of the forum members asked about dirt contaminating the oil.
The analysis also gave a %insolubles which is supposed to be below 2.0%, and mine was still less than 0.6%.

C5 Curmudgeon

I'm not surprised. Thanks for sharing the information!

JeffC5

Thats good info to know. Thanks for sharing.
jeff

lvvette777

So you are saying my 3 oil changes in 6000 miles is overkill?

Jetspeedz

very interesting analysis.. i personally change the oil every 3k miles regardless b/c thats what i have always done in all my cars... but every 2k miles on the bike b/c i ride them so hard

Dave68

I change my oil and K&N filter every year (5500 miles). It just doesn't make sense to change oil needlessly.

screw991le

Most car companies are now getting away from the oil scam of 3/3000. Most companies now like BMW and such are saying 15k or 1 year. Now I don't know about you, but when is the last time you've seen a bimmer that breaks down due to an engine problem before 200,000 miles. My last Bimmer got 135,000 and I changed the oil when the computer said to at 15000 miles. So take it for what its worth.

JoshVette

What about dirt?

Doesn't that oil get a little dirty after all those miles and not lube as well as fresh oil??

Shylor

That is what an oil filter is for. Why people can't just get it that 3,000 mile oil changes is just way to soon for synthetic oil. If this concerns anyone then just change the oil filter sooner. Me, I'll trust the oil life monitoring system.

BoYD

Forget BMWs...heck, even my gf's VW Jetta only needs an oil change every 10,000 miles.

It's called SYNTHETIC OIL people. Lasts much longer.

FRCTony

Good info!

I have always found it amusing that many folks who are so concerned about the environment have NO PROBLEM wasting a non renewable resource every 3K miles.

I DO completely understand why someone would spend money needlessly to protect their beloved Corvette

IMHO, if your going to pay for synthetic, you should get your dollars worth!

I plan to let the DIC tell me when to change it.

John Shiels

I had my car done also by Blackstone Labs. 1500 miles of TRACK event use only. Thats redline or on the brakes. They told me I could go 2500 at least with Mobil 10/30. Wear was below normal. I did my Dodge Cummins with 67K on it and they told me go to 8500 instead of the 7500 I was going with Valvoline 15/40 non synthetic. Some Cummins guys are going 30,000 with filter changes only and just adding what is needed.

Madkarter

i was at a gm school and ask the powertrain engineers about this very question. what they said is that marketing had more to do with the recomendations than anything else. we no that the oils will last along time, but its the contaminits from blow by in the rings that degrade the oil. because of fuel injection and computer controls the engines burn alot cleaner causing less contaminits. so you can extend your your oil changes alittle. with my baby i change it every 3000 miles.

schpenxel

Had an argument about this very subject with a local guy a few days ago...

He claimed his integra? or whatever ricey car he was driving needed the oil changed every 3k miles as did every car. especially "high performance cars". I told him the oil llife monitoring system on the vette told me a lot longer and was still a very safe estimate of the oil's remaining life and most car manufactures were even saying 7500+ miles was fine and even reccomended. He claimed that they only said that so cars would wear out faster and I was wrong and was going to ruin my car. I told him to do an oil analysis on his 3k mile oil and he'd learn I was right and he was just wasting oil. He insisted that I had no idea what I was talking about since he's been "working on cars his whole life" and has never heard of an oil analysis..

I've got 4 cars over 150K miles, including the vette. 250K+ on a dodge stealth, 210K on a dodge dakota, 190K on an infinity G20 and 160K+ on the corvette. The sad part is he's a moron, I killed him in the argument and he'll never know it...

blkvett01

Well i have said this for a long time. Being a Engineer both ME and CE. I have not Change my oil by the 3/3000 from the start. My first Vet being a 1968 427 L88 Change oil every 12,000 miles. Have not change yet, but i did start using the oil life monitoring system from the get go.
The oil companys still control everyones life with high fuel cost, And Big Profits! SO Keep changing oil every 3/3000 The CEO of Mobil needs Better profits, to help him keep his Big Pay Day. Many things cause engins to fail most time it has nothing to do with the oil! But this again is my Two Cents and is not Worth much.

TEXHAWK0

The % insolubles was also in the analysis. The normal range is below 2.0%, and mine was still less than 0.6%.

Madkarter

the oil company's have nothing to do with it. the car company's want there cost per mile on maintance to be low for car and driver magazine comparisions. when you ask real engineers and see the cringe on there face on the knew oil change intervals recomendations. you be the judge. yes oils last longer, yes engines burn cleaner. yes you can run your oil longer than 3000 miles.but i am not going to take a chance with my baby.

blkvett01

Well hate to see the Real Engineer thing! But each to there own My Engineering back ground is in Designing A/C Chillers and not car egines, but it seem i must be some what better. My chillers in some case never have to have the oil changed! That is in the life of the chiller Over 20 years. Also with my Degree in Chemical Engeering It seems that i have Done some good. PS just filter changes no oil. Also some heavy equipment companysare going to no oil changes too. I am in no means trying to emply for anyone to not change there oil as often as they wish or feel that is good! I only try to valadate for those who wish to change there oil less often and would like too feel that it is ok to do so. That is why i post a reply when these post come up! Some here want to know it is ok to change oil At 12,000 mile and not 3000 miles.
It is ok! It is also ok that some one wants to change there oil every 3000 mile for there baby, This is ok also!
Just ones Two Cents Not worth much.

BWP 5P

I read on the C6 forum where some guy changed his @ 25 miles....then was going to do it again @ 500, then 1000

What a waste, when you could be driving instead

Shylor

That sort of an oil change schedule cracks me up! People can read the facts and still don't get it. Oh wait I forgot, they call it "Cheap Insurance".