Ruler89

I know that there have been numberous threads on this issue, but here is a viewpoint that should help some of us feel a little better about not zeroing out the oil life monitor:

Oil Change Intervals
With improved technology, does the old mantra of 'every 3,000 miles' still apply? by Larry E. Hall

Most of us already know that regularly scheduled oil and filter changes are a vital part of routine car maintenance that is necessary for engine longevity.

During the miles between changes, the oil in your vehicle's engine gradually becomes contaminated with soot, metal particles, gasoline and other impurities. As mileage accumulates, so do the contaminants in the oil. Eventually, enough impurities accumulate that the filter cannot remove them and the oil cannot keep them in suspension.

When this happens, the resulting sludge can dramatically shorten engine life.

Even though modern technology has vastly improved engines and the oils that lubricate them, regularly scheduled oil and filter changes are still a vital part of regular, preventative auto maintenance. The question is: Just how often does the oil need to be changed?

At regular intervals
The old mantra of responsible motorists that said, "Change your oil every 3,000 miles!" is being replaced. Today car manufacturers' recommendations for oil changes range from 5,000 to 7,500, or even 10,000 miles for many cars when operated under "normal" driving conditions—more often if conditions are "severe."

Before you relax, let me point out that the way most of us drive is listed as severe by the automotive experts. According to the owner's manuals of many new cars and trucks, normal operation of a vehicle is at least 20 minutes, at a medium speed with a steady throttle, and in a clean environment.

According to one car maker's owner's manual, the oil change interval is seven months or 7,500 miles under normal driving conditions, three months or 3,000 miles under severe conditions. This is how severe is defined in the manual:


Repeated, short distance driving.
Extended periods of idling or low speed operation.
Extensive use of brakes.
More than 50 percent driving in heavy city traffic during hot weather above 90 degrees F.
Driving for a prolonged period of time in cold temperatures and/or extremely humid climates.
Driving in dusty conditions or sandy areas.
Driving in areas where salt or other corrosive materials are being used.
Driving on rough or muddy roads.
Driving in mountainous areas.
Well, it looks like the old mantra about oil changes isn't out of date after all. But what about synthetic oils, don't they extend oil change intervals?

Several car manufacturers do recommend synthetic oil for their high-performance models because of the superior protection from friction and extreme temperatures. The protection comes from the processing required to manufacture the base stock and the different additive packages they require.

Despite this better performance, synthetic additives wear out just as they do in conventional motor oils, and need to be changed. The key is driving conditions — normal or severe.

How about just changing the oil filter, can a car be driven farther between oil changes?

Changing the filter is great, but the oil must be changed along with it, given that the oil's additives wear out and contaminants get into the oil itself. The filter can only capture the bigger particles suspended in the oil, not replenish spent additives.

Pinching pennies
From an economic point of view, it would appear that waiting an extra few thousand miles between changes will save money. For example, based on $25 oil changes every 5,000 miles instead of 3,000 miles, more than $300 is saved per 100,000 miles. Sounds pretty good, but if you drive the average of 17,000 miles a year, it will take you almost six years to reach that mileage — or $50 per year savings.

Extending the oil change interval beyond what the manufacturer recommends can seriously shorten the useful life of your engine, and cost you several times that $300 savings. Just ask a professional service technician how often he or she changes the oil and filter on their personal vehicle. Chances are the answer will be 3,000 miles.

That's the answer given by Don Beyer, automotive services director for AAA's Washington/Inland chapter. Beyer, an ASE master technician and former repair-shop owner, says that it is imperative to change the engine oil and filter every three months or 3,000 miles. "I'm doubtful that anyone, regardless of where they live, drives under the normal conditions defined in owner's manuals."

Bottom line: Don't push the limits of motor oil and flirt with damaging your car's engine, especially when chump change is all it takes for an oil change.

Larry Hall writes about cars and the automotive industry from his home in Olympia, Wash.

IMQUIK

Good info. but it's old news to Amsoil.
Home of the yearly oil change since 1972

Cajundude

I've ignored about 90% of the people on the forum that say "change it when the computer says so." Well, not me. I change my oil every 90 days whether I have 500 miles or 2500 miles. Besides, with the way C5s eat oil you would be a fool to run it that long without changing.

I just won't do it, I won't let my DIC tell me what to do. So there.

Grumpy

it seems like you're on the fly oil changing..67K and no oil usage problems

Cajundude

Actually, I don't have it either, just read about it here a lot.

CCA Corvette Parts

3000 or when ever I need a break from the wife and kids!!!

Peace
Willfulone

Dave68

That's the answer given by Don Beyer, automotive services director for AAA's Washington/Inland chapter. Beyer, an ASE master technician and former repair-shop owner, says that it is imperative to change the engine oil and filter every three months or 3,000 miles. "I'm doubtful that anyone, regardless of where they live, drives under the normal conditions defined in owner's manuals."

Obviously, this guy had never had his oil analyzed. Anyone who would make a blanket statement like that is ignorant of modern oil and filters. Even the auto guru at Popular Mechanics magazine recommends dino oil changes at 5000-6000 miles.

mcronec5

Thats funny, I change my every 5000 miles and mine has yet to use 1 drop of oil. I'm now at 56,800 miles in my 98. If "C5s eat oil" then I must have a special engine.

DidntSettle

I change it when the DIC tells me to, in both the 98 coupe and the Caddy. 70K and it burns no oil between changes.

Patman

I just went 6100 miles on my last OCI, using Castrol 0w30, and my oil analysis came back showing lots of life left in the oil, and almost zero contamination in it. My oil life monitor said 18% oil life left, but I'd bet it would go well beyond 0% and still be fine.

Anyone changing their oil every 3000 miles is simply wasting their money. It's not necessary, and you're not going to extend the life of your engine over someone like me who goes 6k or more.

FWIW, my engine doesn't use any oil, I did not need to add anything during that 6100 mile interval.

Tom/99

2,500 miles in the Vette, with synthetic oil and 2,000 miles in the others with conventional oil.

Vetteman Jack

I change mine at about 4500 miles - so far so good. The DIC shows an oil life of about 45% remaining at that point. Good enough for me.

WhiteC5Vette

"Beyer, an ASE master technician and former repair-shop owner." The hell with a master certified technician. Being an ASE certified master technician does not make one an engineer.
I change my oil at about 10-15 percent on the oil life indicator. I would change at zero, but the computer cannot determine how much dirt might have entered the engine.
GM has spent a fortune on testing and calibrating the accuracy of their oil life monitoring systems, and they are pretty darn accurate. Besides, my oil analysis I have run every other oil change shows that the oil is still good for about another 3K.

BiggieBoy

Once a year, which is approx. 4000 miles of driving my '98 C5. One year I totally forgot to the change oil. That was 2 years and 6000 miles of driving between oil changes. When I finally woke up and changed the oil, it was almost as clean as the new stuff I was putting in the car. The oil level was down 1 quart, so that was not bad (no, I didn't wait 2 years to check my oil level--I check it about once a month). There was no noticeable condensation in the oil either. Ya, I think the "change your oil once every 90 days/3000 miles or your car will blow up" is a lot of hot air. With the new high performance engine oils and modern engine building methods & materials, I believe that thinking is "out the window."

dooscoop32

Most people don't keep a car long enough for any of this to matter.

CRVETTE

Evil-Twin

Use The Oil Life Monitor!!!!!!! It Works....

VETFVER

Two and three thousand mile oil changes are old school. Oils have come a long way since the 60's and 70's. Company tests show oil can last 5,000 to 10,000 miles easily. I think we should follow guidlines in the OM. I'm a once a year guy because I can't get enough miles between changes.

If you can see the stick through the oil, there is some life left. If you can't see the stick, change it no matter how many miles you have on that oil change.

My 2 cents.

Dan

dbirdhouse1

According to my patron saints of cars: Click and Clack of "Cartalk" fame, the 3,000 mile limit is bunk and a waste. It does make me shake my head when I use it as an excuse to get out of the house and go for a drive by myself every three months.

Bill Dearborn

As we used to say in school that is the perfect case of quoting a false authority. Certified ASE Technicians may be good mechanics and able to build an engine but they are not certified to design an engine and no automaker in the world would hire them to do so.
Bill

ddisd

I agree - I trust the other sensors/gauges on the car so why not the oil life one. Seems like if GM had messed this one up we would have heard about it by now. Sounds like most people are getting there oil tested with favorable results...... Unless everyone is lieing about that...... Anything's possible I suppose