Having a discussion about extended OCIs with a friend who is a crack mechanic. Seriously, he's probably the most sought after mechanic in the area and has done a lot of racing. He had two sweet '66 hemi Chargers...one to race and one to drive around to shows and on Sundays.
To paraphrase his argument, dirty oil is dirty oil. Even if using a high quality synthetic that may have a lot left to it after 6, 7, 8 thousand miles, once it starts to get dirty the best thing you can do is change it. Changing any motor oil after no more than 4-5 thousand miles (he uses nothing but Castrol GTX changed at 3,000 miles in his vehicles) is the best thing you can do for your car.
Opinions?
Mikep
Is this a valid argument against extended drains?
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Sounds like a valid argument! However good synthetics these days are very good in handling contamination so I dont see why you cant go to at least 10k. I mean thats becoming the norm with manufacturers anyway!
And btw, if he was truely in the know about oils, he'd be using something better than Castrol GTX in his Chargers.
Mikep, With the higher quality oils of today and newer engines running much cleaner due to advanced technology, especially compared to a 1966 Hemi ![[Eek!]](images/icons/shocked.gif)
, I believe you can run a good dino oil for 5,000 miles and still be ok. My wife's Explorer used Motorcraft 5W-30 @ 5,000 mile OCI and it still had some life in it yet. Her UOA was also good. Just because an oil "looks" dirty doesn't mean it is used up. What's making the oil look dirty is particles held in suspension that are usually too small to cause wear. An UOA will tell whether the oil is worn out. As far as going 10,000+++ mile OCI I'm still not sold yet. But I believe with a good quality oil, usually synthetic or a semi-syn like Schaeffer's, you can easily do 7,500 mile OCI's. Be gentle with me fellow BITOG's because I'm a half century old and it takes a bit for me to change my "ways" of thinking ![[Big Grin]](images/icons/grin.gif)
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Whimsey
, I believe you can run a good dino oil for 5,000 miles and still be ok. My wife's Explorer used Motorcraft 5W-30 @ 5,000 mile OCI and it still had some life in it yet. Her UOA was also good. Just because an oil "looks" dirty doesn't mean it is used up. What's making the oil look dirty is particles held in suspension that are usually too small to cause wear. An UOA will tell whether the oil is worn out. As far as going 10,000+++ mile OCI I'm still not sold yet. But I believe with a good quality oil, usually synthetic or a semi-syn like Schaeffer's, you can easily do 7,500 mile OCI's. Be gentle with me fellow BITOG's because I'm a half century old and it takes a bit for me to change my "ways" of thinking .
WhimseyI wonder how he knows the oil is dirty? Does he do an analysis too find out how many insolubles are in the oil? Or does he judge it by color? Some engines will turn the oil black before 1,000 miles. Why does he say 3,000 when every engine treats oil differently? Some engines will still have clear oil at 3,000 miles - does he change these too.
As stated before, most mechanics are just that, MECHANICS. The may do a very good job of diagnosing problems and fixing them, but they know very little about lubricants and how they work. Do they do harm by changing the engine oil at 3,000 miles, no - at least to the engine. I have a locally reputable mechanic work on my truck - he uses Harley Davidson's Syn3 in his bike because it says Harley, Harley says it's better than conventional oils, and he can afford over $8 per quart. I use what I, and many other consider to be a better synthetic and cheaper because, with the help of many people here, I have educated myself about lubrication. Once again, this guy is a great mechanic, but doesn't know a thing about lubrications.
Don't forget about the filter, isn't the idea of a filter to clean the dirty oil? If you have a bypass filter, you should be able to go many miles beyond 3,000 without an oil change.
Most owners manuals now recommend 5k - 7.5k OCI's. A few even go up to 15k miles OCI's. Do you think the manufacturer would recommend this if it was going to damage the vehicle? 5,000 miles isn't really considered and extended OCI anymore.
[ November 29, 2003, 05:11 PM: Message edited by: medic ]
quote:I used to believe that until I found this board. For all the above prescribed reasons in this thread, too. Should a baby's diaper be changed when it starts to become wet? If so, we'd be changing it every hour. We wait until it's "dirty", then change it. The better the diaper, the better it retains the contaminents but doesn't discomfort the little one. I have 2 kids under 4 years, it's the best analogy I could think of!
Originally posted by mikep: To paraphrase his argument, dirty oil is dirty oil
![[Smile]](images/icons/smile.gif){kind=icon}
The oil should be changed when it's "dirty" otherwise, it's a waste of money. Dirty oil is dirty oil, but only when a UOA provides evidence that it's dirty. The old-school method of eye-inspection just doesn't work any longer, there's too many chemicals and variables nowadays.
quote:Why? Castrol GTX, Pennzoil, and Chevron Supreme are the 3 best dino oils in most of this boards opinion...
Originally posted by Leo: And btw, if he was truely in the know about oils, he'd be using something better than Castrol GTX in his Chargers.
First let me say this guy is not a 70 y/o mechanic who grew up fixing Edsels in his back yard. In fact, he's about 48-49 y/o and a very educated bloke (holds a degree in electronic engineering from NJIT). Just to give you'all an idea that he's not exactly out of touch with modern times.
As far as GTX...I don't think Castrol GTX needs me to defend it. It has a proven track record as being one of the top dino oils available. I know there have been some very good UOA here with GTX. I'm not sure, actually I doubt, he used GTX dino in his racing hemi Charger. That wouldn't matter anyway as he probably changed it after every few races if not sooner. I know he does use GTX dino in his non-racing vehicles.
So there are some who agree somewhat with what he says but that modern oils in modern engines can really handle the longer interval. Still, would anyone disagree that the best thing you can do is change the oil after 3000 miles? I mean what would be better, M1 at 10,000 or GTX every 3-5,000? Personally, I know I'd be in the GTX camp.
Mikep
Originally posted by medic:
quote:Absolutely. The automotive industry only makes money if it can sell and service vehicles. They will specifiy a maintenance schedule that will get a vehicle beyond it's warranty period. Anything beyond that is profit for them. Joel
A few even go up to 15k miles OCI's. Do you think the manufacturer would recommend this if it was going to damage the vehicle?
quote:OK, consider this, in the 40's and 50's, the average passenger cars OCI was 1000 miles. Yes, every 1K. So 20 years later, oils were more 'modern' and could handle a 3k interval. now, 30 more years later oils are even More modern. Do you think we need to change oils every 1000 miles, because it is safe? Now consider this.....(Poor example, but you get the idea on it)you have a can of Coke. you open it. 15 minutes later, you figure the Coke is now bad, because it was exposed to the air, so you throw it out. well, some person sees you doing that and says, hey, that Coke will stay good for 45 minutes, why you throwing it out? he proves it by waiting 45 minutes and pouring it into a glass. it fizzes just as good as your 15 minute Coke does. Well, thats how the Extended oil changer feel, We just prove it by doing UOA's and such to make sure it is doing its job as well at 5k as it does at 3k. Not that it is 'wrong' to change at 3k, but is it better when the 5k product is working just as well?
Originally posted by mikep: So there are some who agree somewhat with what he says but that modern oils in modern engines can really handle the longer interval. Still, would anyone disagree that the best thing you can do is change the oil after 3000 miles? I mean what would be better, M1 at 10,000 or GTX every 3-5,000? Mikep
quote:Very well said Tim H. Mikep
Originally posted by Tim H.: OK, consider this, in the 40's and 50's, the average passenger cars OCI was 1000 miles. Yes, every 1K. So 20 years later, oils were more 'modern' and could handle a 3k interval. now, 30 more years later oils are even More modern. Do you think we need to change oils every 1000 miles, because it is safe? Now consider this.....(Poor example, but you get the idea on it)you have a can of Coke. you open it. 15 minutes later, you figure the Coke is now bad, because it was exposed to the air, so you throw it out. well, some person sees you doing that and says, hey, that Coke will stay good for 45 minutes, why you throwing it out? he proves it by waiting 45 minutes and pouring it into a glass. it fizzes just as good as your 15 minute Coke does. Well, thats how the Extended oil changer feel, We just prove it by doing UOA's and such to make sure it is doing its job as well at 5k as it does at 3k. Not that it is 'wrong' to change at 3k, but is it better when the 5k product is working just as well?
It all depends on too many factors. The age of the vehicle, the type of engine, the type of oil, driving conditions, all of those things and more.
If you are just driving around town, especially in cold weather and short trips, 3000 miles or three months is probably good advice.
If you are a travelling salesman and putting a lot of miles on your vehicle, 6000 miles or more would be okay.
And what kind of oil are you using? Synthetic or conventional? And quality of oil. There IS a difference. With some conventional oils, it might be a good idea to change the oil every 2000-3000 miles. With others, you could probably easily go 5000 miles.
Patman
Staff member
In my opinion, every situation is different. Some situations call for a 3k oil change, even with synthetics, such as if you do a lot of short trips and might take a year to reach 3k. But then there are other situations where 3k oil changes are downright crazy, such as if you drive 500 miles per week all highway.
There is no "one size fits all" when it comes to OCIs and it's all about your own comfort level too. I know my own situation would allow me to go 15,000km intervals (9300mi) most likely, but I'm most comfortable sticking with 10,000km intervals for now.
All of this talk about all of the variables involved in determining an appropriate OCI brings up a question.....Have any of you found yourselves altering the OCI of a vehicle due to a change in driving habits/distance?
Jeep recommends an oil change every 7500 miles for my Cherokee, and that's from back in '90 when it was made. Not saying your friend doesn't know what he's talking about, but the people who design the engine/oil know more. If they recommend 7500 on dino oil, 8000 should be ok for your average idiot, and 10,000+ should be just fine with synthetic. I still change it every 3k or less though...while it isn't necessary, it's not going to hurt anything either.
3 to 5,000 mile oil changes seem proper to me. Changing oil often is a very good thing. An oil anaylsis is the only way to check if the oil is holding up and the cost would cover a good chunk of the oil changes cost. I am not saying that syn oil won't last but frequent oil changes do only good.
He is right and wrong.
In the old days, there was a thing called 'bore wear'. Very badly designed air filters, carbs and chokes that allowed fuel and dirt/dust to contaminate the oil,as well as washing all the oil from the 'bores'.
Many motors needed re bores in as little as 160,000 miles. Oil got contaminated and needed changing far more frequently.
Today in a modern well designed fuel injection motor, things stay really clean in side.
It is quite normal in a high quality motor to still be able to see with a bore scope, the original cross hatching on the cylinder walls after 100,000 miles. This proves to me that oil is staying cleaner longer and thus can take extended changes far better than in previous years.
Add to this equation the greatly improved oils and you have a win win situation.
I could change my oil every week, or I could change it every 60,000 km like my manufacturer recommends. Something inbetween is probally best. Driving 21,000 miles a year equals three synthetic changes or seven dino changes for me. My car has an oil service light to reset, a underbody cowl to R&R also the trouble of recycling the oil makes it well worthwhile to let the dealer change it for $15 + filter, 3 times a year. 7 times a year would not make more sense and my engine is just fine. My point is: not all cars are cantidates for 3000 mile dino changes anyway. ps If your mechanic is such a pro, ask him what IS the longest OCI he has ever heard of. If he does'nt even know what Audi and BMW set as an OCI, how can he even comment on it? Boosted, multi-valve, multi turbo, alloy engines are a bit different than low-revver, pushrod V8s as far as oil goes anyway, and they go 10s of thousands of miles based on FACTORY research and testing. Something to think about.
[ November 30, 2003, 12:47 AM: Message edited by: TSoA ]
quote:I think the key part of the quote is "dirty oil is dirty oil". Considering just this aspect isn't it better to get the dirt out of the engine, even if the oil is still fuctional? Dirt would also be things that the filter can't catch. The question is how often is enough. This guy thinks 3000 is enough. I tend to go a little longer and still sleep. But more often would have to be better. And I don't think the toilet paper filters solve all problems either; seems like the oil still will get contaminated with those. Combining these super filters with short changes would probably be the the ultimate. But then again shorter intervals would still be better. So where to stop? For him aroung 3000 and for me 4000 to 5000. Another good question would be, which would be better 3000 dino or 6000 synthetic after 200,000 miles? But I don't think he asked that.
Originally posted by mikep: To paraphrase his argument, dirty oil is dirty oil. Even if using a high quality synthetic that may have a lot left to it after 6, 7, 8 thousand miles, once it starts to get dirty the best thing you can do is change it. Changing any motor oil after no more than 4-5 thousand miles (he uses nothing but Castrol GTX changed at 3,000 miles in his vehicles) is the best thing you can do for your car. Opinions? Mikep
Patman
Staff member
quote:Yes. My mom used to drive 500 miles per week, so I changed her oil roughly every 5-6k with Mobil 1. But now she is retired and only drives about 60-70 miles per week, so her last oil change only went 2350mi, and I now have Walmart synthetic 0w30 in there and plan on doing 3k intervals, since it will take her almost a year to drive that far (all short trips now obviously)
Originally posted by SL8Brick: All of this talk about all of the variables involved in determining an appropriate OCI brings up a question.....Have any of you found yourselves altering the OCI of a vehicle due to a change in driving habits/distance?
quote:Exactly his point. I don't know exactly how he goes about determining if the oil is "dirty" but I would guess that he just figures that after 3-5,000 miles it has accumulated some contamination. Personally, I feel comfortable going the 5,000 miles interval on a quality dino. Especially based on the one and only UOA I had done. But I can't fault him (or anyone for that matter) for taking the position that getting fresh oil in every 3,000 miles can, like Steve S. said, only be a good thing. Mikep
Originally posted by White 03: I think the key part of the quote is "dirty oil is dirty oil". Considering just this aspect isn't it better to get the dirt out of the engine, even if the oil is still fuctional? Dirt would also be things that the filter can't catch.
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