How accurate is the oil life in the DIC? Should I trust it or just change the oil everything 3000 miles?

 

With Mobil 1, I change it when indicated but you will get 10,000 opinions. There is no better oil than Mobil 1. It will protect your engine.

 

The DIC reports the percentage of oil life based on the conditions that you subject the oil. Since the engines are extremely well sealed, you can safely get more than 3,000 miles between oil changes if your driving conditions are some what normal. Certainly normal is a subjective term too. If you drive it hard in hotter climates then your oil change should be more frequent than some one who doesn't drive hard. Heat is probably the biggest killer.

I believe the manual recommends 10,000 miles or at least once a year. I use a combination of oil life remaining and time.

 

Your oil is the life blood of your Corvettes engine, I change mine as well as the filter every 3,000 miles if it needs it or not, have you ever seen oil with 10,000 miles on it. It might help you make up your mind.

 

The oil life monitoring system is VERY accurate. GM spent a lot of time and money developing this system and it works. You can safely take it down to 0%.

 

My oil percent life, will not reset more than 77%.
What is wrong?

 

Conventional wisdom is that oil should be changed every 3,000 miles. This conventional wisdom refers to a time when castor oils were used in cars, before petroleum based oils, before synthetic oils - in other words a long time ago. We are talking about the first decade of the last century.

Castor oils are vegtabled based. They are a great lubricant, but don't last very long (they have a very low flash point). This is where the 3,000 mile rule came from - the 1908 period. Somehow it has stuck to this day. Of course it makes no sense today. It is just an old adage. Of course it doesn't hurt to change it that often, just like it wouldn't hurt to wipe your dipstick with a $100 bill after you check the oil and throw it away. Both practices are a waste of money.

A Mobil engineer told me 15,000 miles was an appropriate oil chang interval. I change mine when the DIC gets down to 5%. Following an old, bad habit, I changed mine at 1,000 miles, again at 10,000 miles and at about 18,000 miles (when the DIC got to 5%). I have had to add a quart of oil once between these oil changes.

As a shareholder of Exxon Mobil, I thank you guys who change your oil every 3,000 miles. If that makes you feel good, why not change it every 500 miles. Think how much better you would feel.

I do miss the smell of that castor based two stroke racing gas in my old BSA flat tracker.

 

 

How much cleaning could an oil filter that is 10,000 miles old do? Seems like if you are going to change your oil at such large intervals the filter should be changed more often. No?

 

Or maybe oil filters with 5 or 6,000 miles on them really aren't as dirty as we think.

 

The 3000-mile oil change myth is one that's perpetuated by oil change shops who want your money more often. That's all. Engine technology has come a long way since 1908.


If you use a pure synthetic, you are not gaining anything at all by changing your oil more often than 7000, 8000, or even 10k miles.

You won't HURT anything by changing every 3k miles, but all you're doing is throwing money away *edit* Actually, it COULD be hurting things by changing so often, see my post below*

Go by your DIC. Your car knows when it needs oil.

 

Mobil-1 oil life test: might be an eye-opener to some people

http://neptune.spacebears.com/cars/stories/mobil1.html

One key quote:
Engine wear actually decreases as oil ages. This has also been substantiated in testing conducted by Ford Motor Co. and ConocoPhillips, and reported in SAE Technical Paper 2003-01-3119. What this means is that compulsive oil changers are actually causing more engine wear than the people who let their engine's oil get some age on it.




And if you wanna get really crazy, read about this Mack truck engine tear-down after running 409,000 miles without an oil change, using Amsoil synthetic.

http://www.performancemotoroil.com/409000

 

LOL

 

If you are running a good Group IV PAO based synthetic like Mobil 1 or AMSOIL, and your driving is relatively normal, the oil life indicator is probably the way to go.

I used to be a 3,000 mile/3 month oil guy as well, but after becoming an AMSOIL dealer last year, reading hundreds of used oil analysis reports on engines that went well past 3,000 miles, and studying what the norm is in Europe, running engines not much different than ours, I am now a believer in longer drain intervals.

In my wife's Chevy Trailblazer, I run AMSOIL XL-7500 Synthetic 5w30 and follow the oil life indicator. Last two changes were each six months, 9k miles on one, 6.5k miles on the other. For my F350, I use Series 3000 Synthetic 5w30 Heavy Duty Diesel Oil and am changing the oil at 15k miles or six months, with a filter change at half either.

For my vette, as it sees only track use, I use much more frequent oil changes.

Here are a couple interesting articles on oil change intervals written by the editor of Lubes and Greases. Note, these were writter prior to Mobil's recent release of the new Mobil Extended Performance 15k mile oil, which compares to the 25k mile AMSOIL SAE synthetics.

Motor Drain Intervals: How Long Must We Wait?
Motor Oil Drain Intervals: An Ethical Burden?

 

I'm assuming you are resetting properly, key on, engine off. If that does not work, I don't have a clue.

 

I WOULD NEVER GO LONGER THAN 3,000 MILES, i am in the oil business have been since 1988, for example, bmw says 15k in between changes, had a custromer come in at 15k for the first change, the oil was like black chunky tar, about 2 qts low and the oil filter disinigrated in my hand when i took the canister apart, face it the dealers want the repair work when the engine goes south, and i laughed my *** off when mobil 1 came out with a 15,000 mile oil.... that was too funny...you must really hate your car to change the oil every 15k