What oil percentage do you let your oil get to before changing it out?
05-21-2018, 04:42 PM
#61
The increasingly common spec of synthetic oil in today's cars is a big reason why 200,000 miles is the new 100,000 miles in vehicle longevity. If you're going to keep a car for a long time, it's a VERY good idea to use synthetic oil.
05-21-2018, 04:43 PM
#62
What kills me about this thread is most Corvette owners:
A) Barely drive the friggin cars
and
B) Won't be keeping it until it has high miles anyway
Still, why not take CARE of the car? It's the right thing to do.
A) Barely drive the friggin cars
and
B) Won't be keeping it until it has high miles anyway
Still, why not take CARE of the car? It's the right thing to do.
05-21-2018, 04:47 PM
#63
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When the voice nags me, I get it changed.
Elmer
Elmer
05-21-2018, 05:10 PM
#64
Race Director
My brother was an exec @ Mobil way back in the 70s when they first introduced Mobil One (I think it was 1974, he started with them a few years after that). He knew some of the engineers who had worked on that project. From those stories, it sounds like you could run your Corvette 100K+ miles and NEVER change the oil before you'd start having engine issues. They really did have some amazing R&D stories, like running motors hundreds of thousands of miles with zero damage. That stuff never loses viscosity.
But it does lose viscosity once fuel is introduced into it. When I changed the oil on my 2018 for the first time, at 1100 miles, I had the oil analyzed and because it had 2% fuel dilution, the Mobil 1 5w30 had already thinned out to a 5w20. On my second oil change, the oil had less than 1% fuel dilution this time, but it had already thinned out to a very light 30 weight and that was with only 2000 miles on it (and I don't drive the car super hard either)
05-21-2018, 09:53 PM
#65
Not true. Have you ever had an oil analysis done Joe? I do it after every oil change on every one of my cars and have done so for over 15 years now. And in my experience, there aren't many vehicles that can go 15,000 miles safely on regular Mobil 1, by that point in time the oxidation levels are much too high and the TBN is much too low. (I tried 15k on Euro M1 0w40 in my wife's BMW and the oil analysis results were not good, so I now keep it closer to 6-9k in her car) You are risking having a lot of engine deposits if you go 10-15k, especially with direct injection, which places an even harder stress on the oil. Most engines that use direct injection can't even go much past 7 or 8000 miles without severely degrading the oil, mainly due to fuel dilution.
If people want their LT1 engine to last, definitely do not push the oil beyond what the oil life monitor tells you to do,£ that's just foolish advice you're giving Joe.
If people want their LT1 engine to last, definitely do not push the oil beyond what the oil life monitor tells you to do,£ that's just foolish advice you're giving Joe.
You're just blathering personal opinion here, never having any proof of your snake oil predictions. Mobil 1 is a 15,000 mile oil. In fact, it's perfect for a lot more than 15,000. The LT1 engine is not affected negatively by exceeding the 1 yr./7,500 mile usage factors. If it were, mine would have blown up by now, according to you. 87 octane is a recommendation for the LT1 engine straight from GM. You really need to try to get your head around that fact. You're starting to look silly, making up GM recommended maintenance on your own,, that doesn't exist. 
Last edited by Skid Row Joe; 05-21-2018 at 09:55 PM.
05-21-2018, 10:00 PM
#66
Joe, that is one (of many) of your illogical subjects! No matter who tells you that is not and what is says - you refuse to listen. No new for you! I'll quote the 2017 Owner's Manual for fun:
Page 213-214 PDF version:
"For the LT1 6.2L engine, premium unleaded gasoline meeting ASTM specification D4814 with a posted octane rating of 93 is highly recommended for best performance and fuel economy. Unleaded gasoline with an octane rated as low as 87 can be used. Using unleaded gasoline rated below 93 octane, however, will lead to reduced acceleration and fuel economy. If knocking occurs, use a gasoline rated at 93 octane as soon as possible, otherwise, the engine could be damaged. If heavy knocking is heard when using gasoline with a 93 octane rating, the engine needs service."
Yep you can do that with most engines! Retard the timing that reduces the tendency for knock but at reduced power output. Also operate with a richer fuel/air ratio to help reduce tendency for pre-ignition! So if you really use 87 octane your getting less power and reduced fuel economy! Brilliant!
Page 213-214 PDF version:
"For the LT1 6.2L engine, premium unleaded gasoline meeting ASTM specification D4814 with a posted octane rating of 93 is highly recommended for best performance and fuel economy. Unleaded gasoline with an octane rated as low as 87 can be used. Using unleaded gasoline rated below 93 octane, however, will lead to reduced acceleration and fuel economy. If knocking occurs, use a gasoline rated at 93 octane as soon as possible, otherwise, the engine could be damaged. If heavy knocking is heard when using gasoline with a 93 octane rating, the engine needs service."
Yep you can do that with most engines! Retard the timing that reduces the tendency for knock but at reduced power output. Also operate with a richer fuel/air ratio to help reduce tendency for pre-ignition! So if you really use 87 octane your getting less power and reduced fuel economy! Brilliant!
When the GM Engineers clearly know more than you do, just start making up fairy tales on what you want the Owners Manual to state.
Brilliant!
Last edited by Skid Row Joe; 05-21-2018 at 10:03 PM.
05-21-2018, 11:38 PM
#67
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Joe, that is one (of many) of your illogical subjects! No matter who tells you that is not and what is says - you refuse to listen. No new for you! I'll quote the 2017 Owner's Manual for fun:
Page 213-214 PDF version:
"For the LT1 6.2L engine, premium unleaded gasoline meeting ASTM specification D4814 with a posted octane rating of 93 is highly recommended for best performance and fuel economy. Unleaded gasoline with an octane rated as low as 87 can be used. Using unleaded gasoline rated below 93 octane, however, will lead to reduced acceleration and fuel economy. If knocking occurs, use a gasoline rated at 93 octane as soon as possible, otherwise, the engine could be damaged. If heavy knocking is heard when using gasoline with a 93 octane rating, the engine needs service."
Yep you can do that with most engines! Retard the timing that reduces the tendency for knock but at reduced power output. Also operate with a richer fuel/air ratio to help reduce tendency for pre-ignition! So if you really use 87 octane your getting less power and reduced fuel economy! Brilliant!
Page 213-214 PDF version:
"For the LT1 6.2L engine, premium unleaded gasoline meeting ASTM specification D4814 with a posted octane rating of 93 is highly recommended for best performance and fuel economy. Unleaded gasoline with an octane rated as low as 87 can be used. Using unleaded gasoline rated below 93 octane, however, will lead to reduced acceleration and fuel economy. If knocking occurs, use a gasoline rated at 93 octane as soon as possible, otherwise, the engine could be damaged. If heavy knocking is heard when using gasoline with a 93 octane rating, the engine needs service."
Yep you can do that with most engines! Retard the timing that reduces the tendency for knock but at reduced power output. Also operate with a richer fuel/air ratio to help reduce tendency for pre-ignition! So if you really use 87 octane your getting less power and reduced fuel economy! Brilliant!
It's snake oil when I quote the "page and exact words" that say 87 octane will reduce power and gas mileage and "93 octane is "highly recommended" your unable to read what it says only want to see what you wish!
Keep using 87 octane and why ever change your oil! I was giving you the benefit of the doubt-no longer!
Last edited by JerryU; 05-21-2018 at 11:42 PM.
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speedlink (05-22-2018)
05-22-2018, 12:01 AM
#68
Race Director
Very true, in fact. Your opinion on Mobil 1 wearing out out at 7,500 miles is complete balderdash. Your posts about expert oil analysis on forum are complete bunk. You proved that when you claimed that your old Honda's laboratory analysis was noteworthy, but your new C7's oil analysis wasn't. You're just blathering personal opinion here, never having any proof of your snake oil predictions. Mobil 1 is a 15,000 mile oil. In fact, it's perfect for a lot more than 15,000. The LT1 engine is not affected negatively by exceeding the 1 yr./7,500 mile usage factors. If it were, mine would have blown up by now, according to you. 87 octane is a recommendation for the LT1 engine straight from GM. You really need to try to get your head around that fact. You're starting to look silly, making up GM recommended maintenance on your own,, that doesn't exist.
You're just blathering personal opinion here, never having any proof of your snake oil predictions. Mobil 1 is a 15,000 mile oil. In fact, it's perfect for a lot more than 15,000. The LT1 engine is not affected negatively by exceeding the 1 yr./7,500 mile usage factors. If it were, mine would have blown up by now, according to you. 87 octane is a recommendation for the LT1 engine straight from GM. You really need to try to get your head around that fact. You're starting to look silly, making up GM recommended maintenance on your own,, that doesn't exist.
05-22-2018, 12:59 AM
#69
Le Mans Master
~ 10% or 1 year which ever comes first.
05-22-2018, 01:08 AM
#70
Le Mans Master
This really bothers me. The oil life monitor pushes to have an oil change within a time period as well as mileage.
It seems a waste to change the oil with less than 6000-8000 miles on Mobil 1, just because a year expires.
I still change annually, but to see it go to 0% with only 3000 miles is ridiculous.
It seems a waste to change the oil with less than 6000-8000 miles on Mobil 1, just because a year expires.
I still change annually, but to see it go to 0% with only 3000 miles is ridiculous.
05-22-2018, 07:09 AM
#71
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My brother was an exec @ Mobil way back in the 70s when they first introduced Mobil One (I think it was 1974, he started with them a few years after that).
That stuff never loses viscosity.
I wouldn't lose sleep about going by the manufacturer's book or a little over on this.
That stuff never loses viscosity.
I wouldn't lose sleep about going by the manufacturer's book or a little over on this.
In fact your comment about "way back in the 70s" reminded me of when I started to use Mobil 1, for my 1974 Datsun 260Z! it solved a unique problem I had with those twin large Hitachi SU carbs! I can still remember the Datsun area tech rep, who the dealer asked to look at the car and instantly said when I described the problem: "Yep we call the "porpoising!" If you get this oil the military is using in Alaska it will solve it-it's called Mobil 1!DETAILS (long version!)
1974 was a year the EPA was pressing manufacturers to improve emissions. (It was before CATs and the 1974 454 cid Vette had only 270 hp where in 1969 a 427 cid achieved 435 hp.) Datsun had hot water under the manifold, it had an air pump injecting into the exhaust manifold and was it was very lean. Once it was up to temperature, when you accelerated it would surge forward, they slow and repeat several times! The Datsun tech rep said the SU dashpot oil was tinning out excessively and using a heavy weight oil would hurt responsiveness! The SU is a variable area carb and changes the venturi opening! The more constant viscosity Moibil 1 solved the problem!
Mobil 1 was hard to get and expensive. While reading about it's properties, I was intrigued about it's ability to operate at high temps. My modified Corvair oil was operating at 325+F when pushed. Had installed an oil temp gauge and added finned (internal and external) aluminum pan and valve covers but not much help. It would form a scum on the oil intake tube! It was breaking down. Mobil 1 solved the oil problem in the Corvair that was my "winter car" as I was living along Lake Eire in NE Ohio at the time.
I'll mention my Canadian connection for you as it just came to mind! Since Canada had 4 large pipe mills producing 20 to 48 inch diameter gas and oil transmission pipe, spent quite a bit of time supporting our Canadian welding business. The pipe is made from flat sheets formed into a pipe and the seam welded in two passes one from each side. Recall giving a technical talk about a 3 electrode arc welding system I developed that operated at a total of ~3000 amps and doubled the manufacturing speed! The seminar was at a resort and a day before my talk was with our Canadian engineering manager and good friend in a small boat on a Lake at the resort. I recall he said something about my Zed! First time I heard Z produced that way! I said I was thinking about buying a 2 year old used CJ5 Jeep to replace my 9 year old Corvair. My friend said do-it, you only live once! I did!
Too bad Mobil 1 changed in ~2000 from all man made molecules [polyalphaolefin (PAO)] to a "more highly refined dino oil!" If you want all the details this is a good article on the subject from Car & Diver mag:
https://www.caranddriver.com/columns...mantics-column
Fun read. You'll see Mobil (and others) were forced to as Mobil lost a suite to Castrol who was calling their "dino oil" synthetic! It cost half to produce. I have been using it ever since! Perhaps not as good but much cheaper than in 1974!
Last edited by JerryU; 05-22-2018 at 07:23 AM.
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JerryU (05-22-2018)
05-22-2018, 10:26 AM
#73
Team Owner
Living in the mountains of upper NYS and storing my car for a few months it works out quite well to get my oil changed (once yearly) just before it goes away for the winter. I normally put on under 5,000 miles a year! (its a 3rd vehicle and I pick my times out) Been doing it this way for 20 years with 4 different Vettes!
My (good) dealer does oil change, I drive it home wash it and it sits in garage with tender on.. Dealer also sees it in April when it comes out of garage for NYS vehicle inspection. I live up to the terms of the warranty!
My (good) dealer does oil change, I drive it home wash it and it sits in garage with tender on.. Dealer also sees it in April when it comes out of garage for NYS vehicle inspection. I live up to the terms of the warranty!
05-22-2018, 04:07 PM
#74
05-22-2018, 04:58 PM
#75
Race Director
^^^ I agree. I never understand the logic of people who change the oil once a year but decide to do it after storage. It makes no sense to put the car away in the fall with dirty oil. For extended storage you want the oil to be as clean as possible.
05-22-2018, 05:14 PM
#76
Team Owner
[Makes no difference at all changing it before or after storage.QUOTE=Patman;1597253646]^^^ I agree. I never understand the logic of people who change the oil once a year but decide to do it after storage. It makes no sense to put the car away in the fall with dirty oil. For extended storage you want the oil to be as clean as possible.[/QUOTE]
05-22-2018, 07:22 PM
#77
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Mine gets changed 1 time per year as I put about 1k per year on the car. I had a oil analysis done by Blackstone labs & the report said that the oil was good for many more miles. Here's a big thumbs up for Mobil 1 
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edved (05-22-2018)
04-01-2019, 06:37 PM
#78
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My brother was an exec @ Mobil way back in the 70s when they first introduced Mobil One (I think it was 1974, he started with them a few years after that). He knew some of the engineers who had worked on that project. From those stories, it sounds like you could run your Corvette 100K+ miles and NEVER change the oil before you'd start having engine issues. They really did have some amazing R&D stories, like running motors hundreds of thousands of miles with zero damage. That stuff never loses viscosity.
I wouldn't lose sleep about going by the manufacturer's book or a little over on this.
I wouldn't lose sleep about going by the manufacturer's book or a little over on this.
04-02-2019, 02:59 PM
#79
Pro
Oil change
- I run it down close to 0! I use to change my oil every 3k miles or so. Then my daughter lectured me on how much additional pollution I was making, and the wasting of resources-unnecessarily! I was "old school"!
04-02-2019, 03:06 PM
#80
Race Director
This ties in with what I've read elsewhere. Supposedly the synthetic can run forever the only thing needed to change is the filter. I believe the synthetic oil never breaks down. Over the road tractor trailers supposedly have tested the 100k mileage. And to all that say there's gunk that accumulates in the oil, get it hot enough and it burns away. Thoughts??
Tractor trailers can go 100k on their oil because they have MASSIVE sumps that hold gallons and gallons of oil. So any contamination they get is spread out over a huge amount of oil.
Last edited by Patman; 04-02-2019 at 03:06 PM.