Most oil on the shelf today meets the API spec. There is an acidic byproduct of combustion that contaminates oil.

 

I change the oil in my vette every 300 - 400 miles (or twice a year)

my daily driver has been getting changed every 5,000 miles...

 

What about the oil life monitor. I would assume that some engineering went into the algorithm for that. I have had mine trip in as few as 1600 miles and as long as 10K miles.

 

I used to be a 3000 mile oil guy. Now that I started using blackstone labs for anaylis, I'm going 8000 miles, and the oil still test good.

I had 3 year old oil tested on my car in storage, the oil was fine.

On my track car, I run the oil to 300 degrees every weekend, the oil analysis shows good.

This oil change thing is over rated.

 

I bet my oil would fail miserably at 2000. Luckily it leaks out fast enough that there's always some portion of fresh stuff.

The 5000rpm blowby is just killing it.

I change my gas less often than that.

 

Hu ???

 

what I believe the author is saying is "since none of us is qualified to judge the condition of our oil, it is best to err on the side of caution and change it at least every 5000 miles."

Correct me if I'm wrong, but I believe the analysis only tells you what contaminants the oil has picked up, not the quantity of additives still left in the oil.
I.e. the oil could be "worn out" and still test good for contamination.

No?

Larry
code5coupe

 

The oil analysis reports on many oil components. The current viscosity, contaminants, the amount of wear metals in the oil from the engine wear, and some major components of the original oil additives. If the lab is reputable and it says the oil is still good to use, it should be good. Check out the link I posted previously. Those guys post several of the labs analysis sheets, so you can see how extensive the analysis was.

 

You can get a TBN #, which tells you how much additives are left.
also, the lab will tell you how much futher you can go on the next oil change.

try it, you'll like it.

 

Hey guys,

What is the cost of lab oil analysis vs. oil change?

 

Yep, I'm "OCD" on changing oil.

There is a 'Built In Indicator" on everyones engine dip stick.

See the writing and graduations on your dip stick??????
When you CAN'T SEE THRU THE OIL to read what's on the stick..Ta-Da... IT'S TIME TO CHANGE OIL.
Simple and easy enough any kid on the 'short bus' can make the 'judgement'.

That's all the 'judgement' I need.
I remember way,way way before there was any Jiffy Lube, King Lube, Grease Monkey, etc, etc, etc.
They DIDN'T invent the 3000 mile oil change.

As far as differences in engine 'machining'.....from the 'old days' to now...
Does .001 REALLY mean a heck of a lot in how often your oil needs changing??
I really don't think so.

 

Interesting find newbecorvetteguy. I read through the legal docs from the site and after the settlement, Toyota still recommends 7,500 mile oil changes for normal driving and 5,000 mile changes under "severe" driving conditions. Here is a quote from the after settlement glovebox sticker to be sent to Toyota owners who are covered by the class-action suit.

"Under normal driving conditions, Toyota/Lexus recommends oil and filter changes every 7,500 miles or 6 months, whichever comes first. If driving frequent short trips, in dusty areas, or in very cold weather, Toyota/Lexus recommends oil and filter changes every 5,000 miles or 4 months."

IF you still have an oil gel problem with a Toyota vehicle for up to 8 years after original purchase, and as much as 5 years after the original warranty, and you have followed the above Toyota guidlines, then they will repair or reimburse you. Toyota is still NOT recommending 3k oil changes even after the lawsuit which makes them liable for far longer than the original warranties.

An old pilot friend of mine told me that Mobil1 was originally developed for aircraft. While the usual things like better viscosity control under use and lower pour points were a part of the equation, the service life was one of the number one considerations. With an aircraft, the cost of the materials is nothing compared to down-time for the oil change and the cost of labor for a certified aircraft mechanic to do the work. An oil that could extend service intervals due to superior contamination resistance was worth the extra cost.

That being the case, I agree with what several others here have said, that it is the long term contamination due to condensation inside the engine that needs to be dealt with, and that it is always better to err on the side of safety. How much safety you need or want to pay for is up to the individual. As for me, I make sure my Vette which adds about 5k miles per year (mostly summer), gets all new Mobil1 and filter every year in Sept. I also ensure that it gets started and run to full operating temp at least once a month in the winter. T

You could change your oil every week and still experience engine problems if you let it sit and never get it up to full operating temp on a timely basis.

 

True, but I'd bet money the engine problem you won't have is sludge following the old 3 month 3k mile rule no matter what you do. The problem with these service intervals is what's appropriate is almost vehicle, owner, and type of oil used specific. Someone with a car in good condition using synthetic oil and burning up the highway (that's me) can go a lot longer than a person using dino oil making short trips around town (that's my wife). 7500 miles or more for everyone isn't the safe recommendation. 3 month 3000 miles is the safe recommendation. Car guys like we all are on this forum are pay close enough attention to our vehicles to make an educated judgement where we fall in this. The public at large is not. IMO, that's why some of these Toyota owners and others are running into problems the last few years. FWIW, I suspect it may not even be possible to develop sludge using synthetic oil.

 

How convienent it worked out to an easy to remember, marketing slogan like, 3k/3-months, and not 4500/3-months or 3k/6-months.

Here is the problem I have with the 3-month/3k milege "Universal Oil Change Standard". What scientific reason do you base this on? So far, no one has posted any evidence showing any real documentation for this "Universal Oil Change Standard" that apparently applies to ALL car and truck makes, of ALL gas engine combinations, and ALL oils types used. Whether it is a fully loaded Suburban with cheapo dino, or an LT1 Vette with Mobil1, it's 3k/3-months under city driving conditions. Man that is some universal standard!

Why not 2-month/2k mileage intervals? Or maybe 4-month/4k intervals? Other than "that's the way I've always done it..." what oil company study, current vehicle manufacturer recommendation,, or independent scientific oil analysis by anyone, anywhere, did this "Universal Oil Change Standard" come from?

I don't argue with the point that more frequent change intervals are less likely to allow the oil to reach unsafe contamination/sludge levels. But, at what point does a reality based value superceed a 60s based recommendation?

The 3k/ 3-month recommendation comes from 60s manufacturer suggestions. It is now the 21st century and everything has changed. In order to be more emmissions compliant, the engines have to be more efficient and tighter. That means less blow-by at the rings. It isn't just the clearances that are better though, the alloys that the rings, the pistons, and other internal parts are made of, are significantly different and better. The processes used to make the oils and the oil additives have changed for the better as well. Synthetic oil is so much more stable and less affected by contamination. the combination means you can go much longer between oil changes.

This is America and by Gawd, you have a right to do what you think is best for you and your vehicle. If it gives you comfort at night to adhere to the "Universal Oil Change Standard" and spend extra money on unneeded oil changes, that's your right. As for me, I'll do an occasional oil analysis for science based recommendations and then spend my extra petro dollars on gas to go places.