In Praise Of The Synthetic 5K Mile OCI In 5 QRT. Sump ?

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The more I read and research - the more I come back to the defacto standard of the synthetic oil 5K mile OCI with a good oil filter as being about best if you want to keep a vehicle running past 250K miles . *First , TBN is not the be all - end all in determining how long you should go with an OCI . *Next , by 5K miles of mixed driving (majority of what we all do) the oil is getting dirty , more abrasive with deposits , fuel dilution starts climbing , etc. so the oil should be replaced . *Vehicle manufacturers are in business to sell new vehicles - the 7.5K to 10K mile OCI recommendations are only listed in the OM to get you to 100K miles (in most cases) . *Castrol EDGE EP and M1 EP stating they can do a 20K OCI is marketing (and dangerous marketing at that) only possibly realistic if you do 100% high way travel ; At most I would run a 6K - 7K mile OCI . *More vehicles today (and growing) are GDI / Turbo engines where by the 5K Mile OCI protects against fuel dilution and soot (abrasive) to keep levels down to an acceptable level . *European BMW , Mercedes , etc. OCI's of 10K or more just can't be good for ultimate engine up keep long term unless driven on the German Autobahn full time . *With previous synthetic oil 6K + OCI's with Sea Foam added last 150 miles - oil would get noticeably darker ; at synthetic oil 5K mile OCI's Sea Foam added last 150 miles showed little oil darkening . * With a synthetic oil 5K OCI I notice less metal shavings in my plastic oil drain catcher afterwards versus 6K + OCI's . *Disclaimer* : Your mileage can and will vary from what I have listed - however in modern engines using an approx. 5 qrt. sump I believe the 5K OCI is about the best recipe with a synthetic oil for keeping an engine running well past 250K miles ...
 
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34,435
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popcorn I agree, at least for my user pattern. I stretched my Liberty out to 6K miles based on UOA results, and established 5K was perfect for my Rubicon, again based on UOA results. Having said that I plan on dropping the Liberty back to 5K miles which would set me up on a spring/fall OCI regime and give me a thousand mile cushion. 4,000 miles is all I can run my van due to a lot of short trips. One thing for sure, if someone from my neck of the woods was trying to sell me a used car and showed me they changed their oil at 10K intervals I'd pass on the car. 7,500 mile limits would be my max, and only if the car was what I considered perfect. I don't care what oil/filter combo they're using. I think many people on this board would agree, although be hesitant to comment. hide
 
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WA
Originally Posted by demarpaint
popcorn I agree, at least for my user pattern. I stretched my Liberty out to 6K miles based on UOA results, and established 5K was perfect for my Rubicon, again based on UOA results. Having said that I plan on dropping the Liberty back to 5K miles which would set me up on a spring/fall OCI regime and give me a thousand mile cushion. 4,000 miles is all I can run my van due to a lot of short trips. One thing for sure, if someone from my neck of the woods was trying to sell me a used car and showed me they changed their oil at 10K intervals I'd pass on the car. 7,500 mile limits would be my max, and only if the car was what I considered perfect. I don't care what oil/filter combo they're using. I think many people on this board would agree, although be hesitant to comment. hide
Right there with ya... maybe if my engine was more like a piece of industrial machinery sealed and spinning at low, fixed rpms with a static load, sure I might consider changing the lubricant based on hrs/days. But it's not.. the load and rpms can vary dramatically, contaminant ingress is a constant battle and all this contributes to unpredictable wear rates. This leads me to want to change out the lubricant more often, not less. But to each his own... it's a free country, do what one wants with their ride but as for me, I'm good with my 5k mile oci's.
 
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34,435
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NY
Originally Posted by Mad_Hatter
Originally Posted by demarpaint
popcorn I agree, at least for my user pattern. I stretched my Liberty out to 6K miles based on UOA results, and established 5K was perfect for my Rubicon, again based on UOA results. Having said that I plan on dropping the Liberty back to 5K miles which would set me up on a spring/fall OCI regime and give me a thousand mile cushion. 4,000 miles is all I can run my van due to a lot of short trips. One thing for sure, if someone from my neck of the woods was trying to sell me a used car and showed me they changed their oil at 10K intervals I'd pass on the car. 7,500 mile limits would be my max, and only if the car was what I considered perfect. I don't care what oil/filter combo they're using. I think many people on this board would agree, although be hesitant to comment. hide
Right there with ya... maybe if my engine was more like a piece of industrial machinery sealed and spinning at low, fixed rpms with a static load, sure I might consider changing the lubricant based on hrs/days. But it's not.. the load and rpms can vary dramatically, contaminant ingress is a constant battle and all this contributes to unpredictable wear rates. This leads me to want to change out the lubricant more often, not less. But to each his own... it's a free country, do what one wants with their ride but as for me, I'm good with my 5k mile oci's.
thumbsup I knew I was in good company. I've had this conversation with a good Bitog friend more than once over the years. Our thoughts on the topic are identical.
 
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Virginia
Well I am on my way to 285,000 miles and the longest I have gone was 6,800 miles on Pennzoil Ultra. I agree with you on what you have stated earlier on this topic.
 
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South Carolina
As noted above, the long vs short OCI depends on many factors. I do 5k with my van because lots of short trips and stop/go traffic. The maintenance minder is also pretty close to that and usually shows 20% oil life at 5k. In contrast, my Cad gets 3k OCI, as suggested at http://www.northstarperformance.com/36services.php, because it is known to be sensitive to oil problems. I realize that in both cases the full syn oil has a lot of life left when I change, but I prefer to err on the safe side. Besides, changing oil is a good reason to get out of the house for a while...
 
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Originally Posted by demarpaint
thumbsup I knew I was in good company. I've had this conversation with a good Bitog friend more than once over the years. Our thoughts on the topic are identical.
I think the OP makes a good point in that most passenger cars have smallish sumps. Now if I had a 12 or 13qt sump where the primary filter is the size of a Titan rocket alongside bypass filtration and the majority of my miles were highway...sure, i might consider 10, 15 or even 20k intervals. But most of my miles, aside from the summer months, are NOT highway.. they're city driving. Stop/go...to the store and back. To the kids football game and back.. that's it. And while I don't have a DI engine, blow by and some fuel dilution is still a very real "thing" for even the venerable port injected engine....
 
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34,435
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NY
Originally Posted by Mad_Hatter
Originally Posted by demarpaint
thumbsup I knew I was in good company. I've had this conversation with a good Bitog friend more than once over the years. Our thoughts on the topic are identical.
I think the OP makes a good point in that most passenger cars have smallish sumps. Now if I had a 12 or 13qt sump where the primary filter is the size of a Titan rocket alongside bypass filtration and the majority of my miles were highway...sure, i might consider 10, 15 or even 20k intervals. But most of my miles, aside from the summer months, are NOT highway.. they're city driving. Stop/go...to the store and back. To the kids football game and back.. that's it. And while I don't have a DI engine, blow by and some fuel dilution is still a very real "thing" for even the venerable port injected engine....
The OP made some great points. I don't own a DI engine either, that imo is a real game changer. I agree on your sump size and bypass filtration comments too. But that always begs the question of how many people fall into that category with their daily drivers? Not many.....
 
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SE British Columbia, Canada
Lately I settled in with 5,000 miles on my 6.0 liter Chev. I've averaged 7,000 miles over the past 185,000 miles and 11 years. It doesn't burn oil but is plenty black at 5,000 miles. Some say the soot in the system makes no difference but no one has been able to show me anything scientific other than Base Number. And no, not interested in arguing. I‘ve got nearly 200,000 miles on a vehicle I've owned since new and I just want the best chance in getting to 250,000 or 300,000 miles. Whether it's 14 oil changes or 20 oil changes in the next 100,000 miles, it makes no difference. I like changing oil. smile
 
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4,165
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WA
Originally Posted by Snagglefoot
Lately I settled in with 5,000 miles on my 6.0 liter Chev. I've averaged 7,000 miles over the past 185,000 miles and 11 years. It doesn't burn oil but is plenty black at 5,000 miles. Some say the soot in the system makes no difference but no one has been able to show me anything scientific other than Base Number. And no, not interested in arguing. I‘ve got nearly 200,000 miles on a vehicle I've owned since new and I just want the best chance in getting to 250,000 or 300,000 miles. Whether it's 14 oil changes or 20 oil changes in the next 100,000 miles, it makes no difference. I like changing oil. smile
I think you'll find this article on soot very interesting, i know I did. It's a short but good read if you haven't already seen it. Let's just say soot in oil is no bueno and the oils reserve alkalinity doesn't begin to address the myriad of problems soot poses in the engine/lubricant. https://www.machinerylubrication.com/Read/51/soot-oil-engine
 
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1,166
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south dakota
ChrisD46 I have to agree with you. I usually go about 5,000 or less myself and feel very confident my engines will last a long time. The Corvette gets changed more often than 5000 miles because it is parked most of the time and I like to keep it clean looking on the dipstick.
 
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South Carolina
My history has been change the oil and filter once a year regardless of miles. The Ranger (85k miles) 5-6k. Runs like new with no oil usage. 4Runner (255k miles) 5k. Runs like new with no oil usage. B2500 Van (185k) 2-3k miles. Runs like new with no oil usage. F150 (250k) 1-2k miles. Runs like new with no oil usage. All with synthetic oil and OEM filters.
 

pbm

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8,677
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New York
While I don't disagree with the OPs premise....I don't think running synthetic over dino would make much difference (in vehicle longevity) doing 5K OCIs. On the other hand, the price difference between syn. and dino isn't what it used to be....so why not run synthetic (and have peace of mind should you go longer than planned on the OCI).
 
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Texas
If you are DIY'ing it and purchase oil & filters on sale / close out / or order them , an oil / filter change is relatively cheap " insurance " . On dino oil , I still try for 3000 mile OCI . On Dexos synthetic , I try for 55% & 5% on the oil life indicator .
 

Bud

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2,802
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Texas
Since I only drive about 4500 miles or so a year, I just do once a year changes. If I were to drive more I agree with the OP. Oil and filter would be changed at 5000.
 
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6,608
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FL, USA
I tend to agree. I think many of us have a mixed driving style that warrants a shorter OCI. Both my wife and I live roughly a mile from our jobs, and around 5 miles or less from grocery stores etc. So our vehicles are exposed to short trips more than 90% of the time. Her Jetta is equipped with a Turbo / DI 1.8 TSI so that makes the case even stronger for a shorter OCI. I won't go so far as to say that manufacturers are increasing OCI's to shorten the lifespan of the vehicle, hoping to get you into a new one sooner. I think it has more to do with ease / cost of maintenance for the customer.
 
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1,767
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Toronto Canada
My experience has been different. Many cars/trucks, my father's, brothers, friends and now my children's vehicles have lasted over 200,000 miles with OCI's over 7,000 miles using dino and or cheap synthetics. Mixed driving in Toronto's climate, UOA says the oil is fine. Timing chains have lasted the life of the engine. Vehicles are usually scrapped due to rust. Sumps of modern cars are larger than ever when you consider displacement to sump size. My old GM V8 took 5 litres and now a 2.2 litre ecotec takes the same. Oil filters were changed every second oil change for north American automobiles in the 70's, 80's and 90's according to the manual. Maybe I've just been lucky. Disclosure: I had a timing chain wear out on a 1974 Ford van with a 302 and a lifter stick in a 1979 GM 305.
 
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5000 is a good even number. Another point made earlier is that the average capacity of the crankcase has gone down. Five quarts is pretty normal these days. Driving routines really depend on where you live. Some places get a five or ten car backup because of geese crossing the road. Other places like where I live see traffic backed up for twenty, thirty miles or more just because it's normal.
 
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