When To Change Oil?
Thread Starter
Racer
Joined: Oct 2012
Posts: 271
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From: McHenry Illinois
St. Jude Donor '14
When To Change Oil?
Just got my C5 two weeks ago and I'm still getting used to the message center. The remaining oil life is about 30%. Should I wait until it says "Change oil soon" or should I change it before I get that message?
Also, the owner's manual says to use 91 octane, with 89 as being OK. In Illinois, our mid-range is 89 and premium is 93. I'd prefer to stick with the 89 due to the much higher cost of the 93. Is this OK or should I alternate them to get an average of 91.
My wife loves this car
, especially since she's 5'2" and our previous Vette was a C4 convertible with very high door sills and lots of road noise. Looking forward to some longer trips in it.
Also, the owner's manual says to use 91 octane, with 89 as being OK. In Illinois, our mid-range is 89 and premium is 93. I'd prefer to stick with the 89 due to the much higher cost of the 93. Is this OK or should I alternate them to get an average of 91.
My wife loves this car
, especially since she's 5'2" and our previous Vette was a C4 convertible with very high door sills and lots of road noise. Looking forward to some longer trips in it.
Banned Scam/Spammer
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From: Oklahoma City
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17,'19,'22
If you don't know when it was last changed I would go ahead and change it. Reset the oil life meter and then follow the 1 year or when the meter tells you. Whichever comes first.
As for gas I would stick to premium. 91 is about as high as you can find here and they run fine.
As for gas I would stick to premium. 91 is about as high as you can find here and they run fine.
Advanced
Joined: May 2012
Posts: 74
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From: Connecticut
Technically I guess you could put half 93 and half 89 and get a 91 mix...in my car it's usually 14 gallons to fill up so that would be 7 gallons of each.
What is the price difference? Here in Ohio it's $.10 a gallon between 93 and 89. Is it worth the trouble to save $.70?
What is the price difference? Here in Ohio it's $.10 a gallon between 93 and 89. Is it worth the trouble to save $.70?
Race Director
Joined: May 2003
Posts: 14,137
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From: Iowa
St. Jude Donor '03 thru '26
Welcome to the best forum on the internet
Change the oil and be sure to use Mobil 1 or equivalent oil.
If I was in your shoes, I'd pay the extra for the 93 octane gas. Going higher than 91 is MUCH better than going down to 89. Your C5 will thank you by better performance all while preventing possible detonation.
Change the oil and be sure to use Mobil 1 or equivalent oil.
If I was in your shoes, I'd pay the extra for the 93 octane gas. Going higher than 91 is MUCH better than going down to 89. Your C5 will thank you by better performance all while preventing possible detonation.
Advanced
Joined: May 2012
Posts: 74
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From: Connecticut
I don't daily drive my C5, and when I do, I want to be able to run it to redline without worrying about detonation and the ECU pulling timing. However if you were on a long trip, in cool weather, and going to spend the whole time on the highway in 6th, you could probably get away with 89 or 87.
Burning Brakes
Joined: Mar 2009
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From: GRAYSLAKE IL
Oldtimer
St. Jude Donor '13
I would go with the high octane. Suggest you use a bottle of Techron ever so often to protect against possible gas gauge issues. I use Shell whenever possible (has Techron in it I believe). Good luck & enjoy your Vette!
Le Mans Master
Joined: Oct 2007
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From: Kelso Washington
St. Jude Donor '09, '13, '15
Congrats and welcome.
As suggested, go ahead and change the oil for peace of mind that you know what you got then. Then reset the DIC and follow it.
And I agree to pay out the extra bucks and go with premium. There could be an offset you don't realize with possibly improving your gas mileage as well,.....not to mention pre-detonation. I think it's worth it.
But it's your car.
so....where are the pics??
As suggested, go ahead and change the oil for peace of mind that you know what you got then. Then reset the DIC and follow it.
And I agree to pay out the extra bucks and go with premium. There could be an offset you don't realize with possibly improving your gas mileage as well,.....not to mention pre-detonation. I think it's worth it.
But it's your car.
so....where are the pics??
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Melting Slicks
Joined: Sep 2011
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From: Appleton WI
I'm not sure what part of Illinois you are in but if you plan to park the car for the winter, I'd wait and change it just prior to storage. At least for me, time is limited and I know I wouldn't use 30% oil life in the remaining weeks. (I daily drive my car in the non-snowy months.)
As far as fuel, do what you want. The 91 octane is recommended; not required. You get the best performance with 91+ but your car won't gag and roll over dead if you use 89 and drive the car as a normal car. I use 91+ all the time because I tend to be throttle happy.
You'll get a wide variety of opinions on both your questions. Do what you feel is best. Most of all, enjoy the car!
As far as fuel, do what you want. The 91 octane is recommended; not required. You get the best performance with 91+ but your car won't gag and roll over dead if you use 89 and drive the car as a normal car. I use 91+ all the time because I tend to be throttle happy.
You'll get a wide variety of opinions on both your questions. Do what you feel is best. Most of all, enjoy the car!
Safety Car
Joined: Jan 2005
Posts: 3,675
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From: Hayward (Bay Area) CA
Speaking of all the Gas talk here.... Since we have only 91 available here in the SF bay area, any recomendations on any gas additive to compensate for the 93...? 
Edit: To change oil, I go about 5-6K miles (sometimes 7K). Mobil1 or most high end Full Synthetic oils are good for about that long. I also monitor the DIC and when it's about 20% or so, I'll change, which is about the same milage. I've had an idea that I've started doing now...change the oil filter during the oil change, and then AGAIN after 2-3K miles. Filters are cheaper, and will keep your oil clean for a longer time.... Just a thought....
Edit: To change oil, I go about 5-6K miles (sometimes 7K). Mobil1 or most high end Full Synthetic oils are good for about that long. I also monitor the DIC and when it's about 20% or so, I'll change, which is about the same milage. I've had an idea that I've started doing now...change the oil filter during the oil change, and then AGAIN after 2-3K miles. Filters are cheaper, and will keep your oil clean for a longer time.... Just a thought....
Last edited by Vette_Fan; Oct 15, 2012 at 02:32 PM.
Le Mans Master
Joined: Jun 2008
Posts: 5,284
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From: Rockledge FL
when you change the oil just remember that the oil life meter has been calibrated to be used with the oil that meets the GM spec. it measures, rpm, engine temp, etc etc and uses the GM spec listed in the owners manual as the base for its calculation. Anything other than what is recommended will make the meter inaccurate.
Racer
Joined: Apr 2005
Posts: 431
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From: Buffalo NY
For me it's easy. I change the oil in the spring when I pull it out of storage. Normally put 5-7k a year on the car depending on what road trips I take. When I did drive it year round I followed the DIC and normally changed the oil at 20%.
As far as the octane question, I run 93 pretty much all the time. I have put 91 in before when that was all that is available. As others have said, it would be fine to run 89 but it is not ideal, especially if you have a bit of a heavy foot.
As far as the octane question, I run 93 pretty much all the time. I have put 91 in before when that was all that is available. As others have said, it would be fine to run 89 but it is not ideal, especially if you have a bit of a heavy foot.
Pro
Joined: Jan 2007
Posts: 553
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From: Cape Coral Florida
run 93. gas drops 1 point of octane in about 30 days so if the cars sits do the math. also change all the fluids you dont know when or what was done. esp the transmission and coolant. The dic is only design to get the car to its end of warranty. There are guys on this forum who have pulled there engines apart at 100k and they were sludge monsters. But they change there oil every 7k so ive always been a advocate of cutting the factory maintenance schedule in half and your car will last twice as long. Im 40 years old and been a mechanic all my life and have proven this therory over and over. Up to you
Last edited by superjet701k; Oct 15, 2012 at 10:12 PM.
Melting Slicks
Joined: Jun 2012
Posts: 3,163
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From: Oceanside California
I change at 25%, thats when the oil goes from brownish to a clealy black color in my car. Its usualy around 4,000 to 4,500 miles between changes for me. Could probably wait for 10-15% and be fine with 5,000 mile changes, but the peace of mind is worth doing is sooner.
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From: Wake Forest NC
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If you don't know when it was last changed I would go ahead and change it. Reset the oil life meter and then follow the 1 year or when the meter tells you. Whichever comes first.
As for gas I would stick to premium. 91 is about as high as you can find here and they run fine.
As for gas I would stick to premium. 91 is about as high as you can find here and they run fine.
Race Director
Joined: May 2003
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From: Iowa
St. Jude Donor '03 thru '26
I agree. The DIC (driver information center) will give you a message on when to change oil. But if you don't drive it enough in a one year period to get to the point of the oil life monitor telling you it is time to change oil, change it annually. That's what I end up doing as I only put 3-5K miles on my car a year - I change the oil right before it goes in storage for the winter.
Burning Brakes
Joined: May 2004
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From: Frederick Md
[QUOTE=3sACROWD;1582080789]I'm not sure what part of Illinois you are in but if you plan to park the car for the winter, I'd wait and change it just prior to storage. At least for me, time is limited and I know I wouldn't use 30% oil life in the remaining weeks. (I daily drive my car in the non-snowy months.)/QUOTE]
I change my oil every year on my 98 which I am the original owner and the car now has 26,000 total miles on the darn thing..
My older 5 Corvettes get the oil changed 3 times a year ...
ALL of them get the oil changed no matter what in November before I store them for the winter..and all get that oil changed in June also no mater what...
Overkill you bet...but I like messing around with my Corvettes almost as much as I like driving them..
Bob G
I change my oil every year on my 98 which I am the original owner and the car now has 26,000 total miles on the darn thing..
My older 5 Corvettes get the oil changed 3 times a year ...
ALL of them get the oil changed no matter what in November before I store them for the winter..and all get that oil changed in June also no mater what...
Overkill you bet...but I like messing around with my Corvettes almost as much as I like driving them..
Bob G