Oil change interval
Thread Starter
Racer
Joined: Sep 2005
Posts: 260
Likes: 0
From: Wheaton Illinois
Oil change interval
What is a good oil change interval for our cars? On my daily driver I change oil every 3000 miles. My C3 only gets driven 500 to 1000 miles a year. I have been changing it every season, am I wasting money?
Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
you have definitely asked a loaded question. there are some that swear that their oil will go bad just sitting there in the oil pan and cause their motor to fall apart if its left in longer than 2 weeks.
others will leave it in for wayyyyy too long.
here is the thing. do an oil change. send in a sample of the oil to be tested. there are a multitude of labs out there that will test your oil.
they will tell you whether or not that oil is still good. their simple test will tell you if the oil is still working to protect your engine and recommend a longer or shorter oil change interval. your oil is either protecting your engine or its not. the test will tell you one way or another.
there are some that will say that they can tell if oil is bad by the color.
me i will put my faith in scientific measurement.
there are some that will say that oil will go acidic if it is left sitting in a crankcase too long.
now bring on the controversy
others will leave it in for wayyyyy too long.
here is the thing. do an oil change. send in a sample of the oil to be tested. there are a multitude of labs out there that will test your oil.
they will tell you whether or not that oil is still good. their simple test will tell you if the oil is still working to protect your engine and recommend a longer or shorter oil change interval. your oil is either protecting your engine or its not. the test will tell you one way or another.
there are some that will say that they can tell if oil is bad by the color.
me i will put my faith in scientific measurement.
there are some that will say that oil will go acidic if it is left sitting in a crankcase too long.
now bring on the controversy
Thread Starter
Racer
Joined: Sep 2005
Posts: 260
Likes: 0
From: Wheaton Illinois
In my case, I have a stock L-82 motor with a 4 speed. While I do like to leave stop lights fast, I tend to baby the car.
I'm up for a good debate, this one has got to be more interesting than trying to justify insurance fraud.
I'm up for a good debate, this one has got to be more interesting than trying to justify insurance fraud.
CF Community Team
Joined: Oct 2004
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From: Cape Cod, Mass.
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Once a year before winter hibernation is a schedule I have followed for many years. I put more miles on than you but that should work for you as well. If the car is sitting and not being short-started the oil will not deteriorate and you're good to go in the Spring.
Team Owner
Joined: Aug 1999
Posts: 30,995
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From: Ontario
I change the oil/filter in October just prior to the winter storage season (dead storage, November to April, no starts). Thus any acidic byproducts of combustion are removed. And it is ready to go for another season in April. About 1,200 miles per mile. An oil change is cheap insurance.
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
I change oil once a year. But as baxsom wrote, if you want an answer based upon the evidence and not opinion, pay about $30 and have your oil analyzed.
Besides, there would be no answer that would give you anything to go on. Some people have issues (rich fuel washdown, coolant leaks, temperature fluctuations...) that can change the outcome and the answer.
Besides, there would be no answer that would give you anything to go on. Some people have issues (rich fuel washdown, coolant leaks, temperature fluctuations...) that can change the outcome and the answer.
Race Director
Joined: Jan 2007
Posts: 14,893
Likes: 3,326
From: NYC NY
When you do drive the car do you go around the block or take it for a ride long enough to bring everything up to operating temperature? Do you start the car up in between just to see if it starts and let it run for a few minutes and shut it down? If that's not the case I would say change the oil before the start of the driving season - use GOOD oil (synthetic) and a high quality oil filter - and I think your car should be fine.
Melting Slicks
Joined: Jan 2003
Posts: 2,713
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From: Shreveport LA
LA Events Coordinator
Is it a conspiracy from the oil companies? 
from the oil filter manufacturers? 
"There is no government conspiracy....because it's all true."
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Le Mans Master
Joined: Jan 2004
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Likes: 75
St. Jude Donor '14
You pose a very good question......When I was younger and was driving (back in the 1970's), it was generally taught that oil changes should be every 6,000 miles. And we did that.... with no apparent problems. Now it's taught "every 3,000 miles for an oil change...Why is that? Is it a conspiracy from the oil companies? from the oil filter manufacturers?
Is it a conspiracy from the oil companies? from the oil filter manufacturers? 
Burning Brakes
Joined: Dec 2007
Posts: 952
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here is the thing. do an oil change. send in a sample of the oil to be tested. there are a multitude of labs out there that will test your oil.
they will tell you whether or not that oil is still good. their simple test will tell you if the oil is still working to protect your engine and recommend a longer or shorter oil change interval.
now bring on the controversy
Le Mans Master
Joined: Jan 2004
Posts: 7,400
Likes: 75
St. Jude Donor '14
Not necessarily true. I could see it being worth a one time expense to see where your engine is in terms of wear. There used to be a company that would take your old filter and cut it open to determine what contaminants are in it. Could be well worth the money from a diagnostic point of view.
Le Mans Master
Joined: Oct 2005
Posts: 6,247
Likes: 471
From: Glen Allen, VA
as several have mentioned, I change mine once a year before the winter, although mine doesn't get stored for the winter. It might be longer periods between drives in the winter, but I will take it out on a sunny day. I put 2-3K a year on mine.
Burning Brakes
Joined: Oct 2006
Posts: 1,006
Likes: 28
From: Lutz Florida
I change the Vette once a year (synthetic) even though it usually only has a thousand miles or less on the odometer. Yes, I know that is overkill but its only a few dollars extra since I do it myself.
My daily drivers used to get changed every three thousand miles but I have upped that to 4500 to 5000 miles now.
My daily drivers used to get changed every three thousand miles but I have upped that to 4500 to 5000 miles now.
Burning Brakes
Joined: Dec 2007
Posts: 952
Likes: 0
Not necessarily true. I could see it being worth a one time expense to see where your engine is in terms of wear. There used to be a company that would take your old filter and cut it open to determine what contaminants are in it. Could be well worth the money from a diagnostic point of view.
Le Mans Master
Joined: Jan 2004
Posts: 7,400
Likes: 75
St. Jude Donor '14
And, I think it is not that much. I saw a website that said from 10- 30bucks.
I wouldn't do it, I suppose. But, I can understand why it could be a good thing.
In a nutshell, it would be strictly preventive maintenance, catching little problems before they get to be big problems.
Melting Slicks
Joined: Dec 2006
Posts: 2,669
Likes: 3
From: Kingston Ontario
Good question! There is no 'one answer' to this one!
I have two daily drivers at my house; and don't maintain them with the same intervals. One gets abused, the other pampered! The abused one gets more maintenance because I want to keep abusing it!
The pampered one gets attention on a reduced level, because that's what it needs.
You have to treat your car to the degree that it requires. If you change your oil once a year and it leaves the crankcase like molasses, in density and color; you may consider changing twice or more in a year. If you flood the engine every time you start the engine you may consider changing the oil every time you start the car!
You need to monitor your situation and determine what you consider to be a reasonable level of maintenance. Every vehicle is different. If you are dealing with a fresh rebuild with excellent tune; you could probably get away with less frequency. If dealing with an original high mileage neglected motor, the oil change change frequency should be considerably greater; unless you are attempting to speed up the rebuild process of the engine.
Le Mans Master
Joined: Jan 2004
Posts: 7,400
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St. Jude Donor '14
I wanted to resurrect this thread to put in a link for oil testing. Basically says what i said earlier, but gives the name of a company that will test oil for about 20 bucks.
http://blogs.carcraft.com/6568035/ed...oil/index.html
http://blogs.carcraft.com/6568035/ed...oil/index.html
Team Owner
Joined: Jul 2008
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From: In limbo
St. Jude Donor '13-'15, '17 thru '22
My car comes to me in a dream, and politely asks me if I would change her oil now. I usually get the oil and filter the next day. I think this is the only scientific way to do it, so I have stuck with it over the years.
More seriously, I change mine every 3000 miles or once a year, whichever comes first. Regretably, this year it was the year that came first.
Although I agree that if you were to drive your car 500 miles per year, the BEST time to change it would be before winter storage, but I think some common sense needs to be applied here. If, for whatever reason, you only had 100 miles on the oil when it got to be time to store, I don't think you need to change it out of some fear of "acidic buildup" in your oil. On the other hand, if it got to be storage time and I had 2000 miles on the oil, I would probably change it myself just to avoid leaving all that dirt and what-not sitting in my engine for 4-5 months.
I think the much more important issue is using a high quality oil, and not what is on sale this week at Walmart.
More seriously, I change mine every 3000 miles or once a year, whichever comes first. Regretably, this year it was the year that came first.
Although I agree that if you were to drive your car 500 miles per year, the BEST time to change it would be before winter storage, but I think some common sense needs to be applied here. If, for whatever reason, you only had 100 miles on the oil when it got to be time to store, I don't think you need to change it out of some fear of "acidic buildup" in your oil. On the other hand, if it got to be storage time and I had 2000 miles on the oil, I would probably change it myself just to avoid leaving all that dirt and what-not sitting in my engine for 4-5 months.
I think the much more important issue is using a high quality oil, and not what is on sale this week at Walmart.
Intermediate
Joined: Jun 2009
Posts: 25
Likes: 0
From: Bend Oregon
Looking at other forums, there is alot of different numbers floating around.
I have always changed the oil in a daily driver at 3000 to 4000 miles and have never had any problems. My wifes BMW runs synthetic and under the warranty, the dealer will change the oil every year regardless of mileage.
So when I get the vette driveable again, I will change every 3000 to 4000 miles. If I'm going to store it over the winter I will go with those suggesting changing the oil before the car is put up for the winter.
I have always changed the oil in a daily driver at 3000 to 4000 miles and have never had any problems. My wifes BMW runs synthetic and under the warranty, the dealer will change the oil every year regardless of mileage.
So when I get the vette driveable again, I will change every 3000 to 4000 miles. If I'm going to store it over the winter I will go with those suggesting changing the oil before the car is put up for the winter.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
Dino oil changed every 3000 miles or every 12 months [whichever comes first] is a safe way to operate. Also, changing it just before periods of minimal use is a good practice. If you use synthetic oil, changing the filter at 3000 mile intervals [use WIX or other good quality filters] and changing oil at 6000...or even 9000 miles should be equally good. Synthetics don't degrade the same as dino oil, and they have a higher tolerance to heat so they will protect for a longer period of time.