Why such short intervals on Synthetic

[blupupher]

quote:

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originally posted by Moving2:
Ray H, blupupher, and others who do shorter OCIs with synthetic for warranty reasons- no response?

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What response do you want? You want me to say OK, I will lie to the dealer if I have an engine problem? I have a friend with a shop that could write me receipts every 3000 miles if I wanted.
Sorry, I do have morals.

I have gone from 3k dino to 7500 syn, an improvement if you ask me. Like I said, I want to go longer but warranty prevents it. I could try a dino for 7500, and may once my stash of free and cheap syn runs out.
The original question was why shorter intervals, and that is why.

And yes, both my vehicles are under factory warranty, one with 10yr/100,000 mile powertrain (changed every 7500 miles, about every 4 months), and the second with 8yr/80,000 mile powertrain (changed with dino or syn blend every 6 months, about every 4000 or so miles).

 

[Cary]

Personally, I think the frequent oil changes using mineral oil is a falicy by people that haven't run the numbers. Lets take the guy that is changing every 3000 miles using mineral oil vs. a 9000 mile oil change interval with synthetic over 100,000 miles.

The guy doing 3000 mile changes buys 6 quarts at $2 a quart (I'm not wasting my time tracking down closeout oils), plus $5 per oil filter. Over 100,000 miles, he does 33 oil changes for a cost of $561. This doesn't include the cost of gas to go get and dispose of the extra oil, or the time to change the oil (roughly 15 hours total if it takes 1/2 hour from start to finish each time).

The guy doing 9000 mile changes with synthetic (6 quarts at $5.50 a quart) changes the oil 11 times in the same period, for a total cost of $422, and only spents 5.5 hours, or half a day less of their life.

Now take the person who pays for the oil change (which I do often because of time). Now the 3000 mile change cost goes from $561 to $1386 (figuring an additional $25 to have the oil changed) while the person doing the synth changes at 9000 mile intervals is only paying $693, exactly half the 3000 mile guy, plus the time saved not waiting for the oil to be changed.

Given that we are simply not seeing sludging issues or other problems with quality synthetics (with the rare exception of things like the VW fiasco which seems to stem from VW not requiring synthetic oil), I do not see the reason to spend the extra time and money. It seems many people are simply continuing on a path that ignores reality because that is what they have always done.

 

[BUBBA0420]

Synthetic or Dino it doesn't matter as it still
gets dirty. I use Dino and change mine every
2000 Miles if not sooner on some of my vehicles
because of time. A clean motor is a happy motor

 

[moving2]

BUBBA- ever done a UOA to see if your oil is suitable for continued use? If not, how do you know if your oil is too dirty to use? As discussed in many previous threads, oil color is often not a good judge of whether an oil is suitable for continued use. Also, many who do extended OCIs change their oil filters halfway through their OCI, which maintains filtering ability.

 

[Jimbo]

A question to late model Corvette owners. Is the recommended OCI longer than other GM cars because of the Synthetic reqirement?

 

[slalom44]

IMHO, the oil doesn't get better as it ages. The filter gets better. Even air filters become more efficient as they are in service, and UOAs have shown this.

New oil filters have large and small paths for the oil to travel. Oil will take the path of least resistance, meaning that the larger paths will see the most oil. As larger particulates plug these paths, smaller paths are traveled, and the backpressure through the filter gradually increases.

If you look at the links posted by AndyH (Thanks!), you will see that the particle increase rate drops as the oil and filter get old:

The particle count also drops when the filter is changed, suggesting that the old filter was getting plugged up. What this graph doesn't show is the size distribution of the particles.

 

[Iain]

quote:

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We often talk here about synthetics ability to handle longer oil changes, but when I look at the UOA's, I see very few people going over 5,000 mile intervals. I would say about 80% are less than 5,000 miles, and 90-95% are less than 7500 miles.

For those that are getting UOA's and finding low wear numbers and high remaining TBN, why are you not extending your interval?

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It's all about convenient numbers for me (5K OCI).

I switched to Mobil 1 last year at 60,000 miles on my Taurus and have recently completed an initial 3K OCI. This current OCI will extend out to 7K with UOA at 5K mark to determine viability of oil.

After this OCI, 5K OCI will simply be a convenience factor in that I will know when to change oil simply by looking at odometer at 70K, 75K....etc.

 

[Tim]

I spend 30 times as much money on gas as I do on oil. Spending an extra $50 per year (a whopping dollar a week!) to do 3000 mile changes on my vehicle instead of 5000 does not register on the meter. My oil is recycled, I enjoy changing it, I lube my driveshafts at the same time yada, yada, yada.

I may talk myself into 2000 mile changes if I keep this up

Cary is correct; most of us could extend our drains. I think I don't because I enjoy putzing on my vehicles.

 

[Tim]

slalom44

Good observation.

I also believe people forget to account for carryover at oil change when comparing wear metal analysis on short drains vs long, on a ppm per 1000 mile basis. Short drains can look artificially bad if they get a couple ppm from carryover.

[ February 28, 2006, 11:31 PM: Message edited by: Tim ]

 

[outrun]

I moon light as Customer Service Advisor to help out my student bills

A came very close to having a blood vessel rupture in me when I told a lady your Pennzoil is good for 5,000 miles at least and to ignore the 3k sticker. I was trying to do her wallet a favor against the outdated 3k oil change racket IMO. That was too much to bear and she yelled at me and accused me of being rude. She got really angry when I explained the tribology and oil science learned here. I went as far as recommending she read BITOG.com here to learn more. I even tried to explain how even older generation oil monitors often trip at 5k+ miles programmed to conventional stuff. The elders here are really cool, but old and arrogant hags self righteous in there 50-60's era thinking angers me deeply. I do not deserve this treatment for being a good samaritan. I am nearing my last straw with people like that ... good incentive to graduate soon and getta the heck out of dodge.

You know the real irony? I often explain to castrol 5W30 & 10w30 users what Castrol did with the NAD decision and how Mobil is PAO etc. The Castrol users always were reasonable and chose M1 instead after the advice. You would think the Syn users would be the most stubborn *lol*

 

[TheTanSedan]

I also think that 7000 miles is a good choice with high quality synthetic and synthetic media filters.

Plus, some LUBE CONTROL and FUEL POWER.

I have a sample rolling around in the glovebox of REDLINE 5w-40 that BLACKSTONE will get at some point. TBN, TAN, all the goodies. 9200 miles, about six months of use and tons of idling in 100F heat. Results may not be great . . I figure it's a little like running the truck out of gas to know exactly what the gas gauge is saying.

I'll let the numbers as read by the analyst tell me what to do next.

I prefer to change it as little as possible, for a number of reasons.

 

[Winston]

quote:

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The elders here are really cool, but old and arrogant hags self righteous in there 50-60's era thinking angers me deeply. I do not deserve this treatment for being a good samaritan. I am nearing my last straw with people like that ... good incentive to graduate soon and getta the heck out of dodge.

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Wait until you get a real job and start suggesting change. Good luck.

 

[wavinwayne]

SO true!!!

 

[Kestas]

Cary, those are nice numbers you presented. While doing some calculations for my car, I realized a lot of the difference in cost comes from using three times as many oil filters with dino when compared with synthetic.

You're assuming the oil filter lasts only 3K with regular oil, but is good to 9K with synthetic. I don't know if that makes a fair comparison.

Perhaps if the oil filter is reused at least once for regular oil changes (I know, it's a repulsive thought), or if the filter is changed more frequently with synthetic oil changes, the costs would tip the other way.

 

[mmcpeck]

I think Jiffy Lube has brain washed a good percentage of the population on 3,000 mile OCI's, as well as a carry over from when oil actually needed to be changed that often, the "old school" thinking.

I know a guy who changes his sythetic oil, based on a 3,000 mile or 3 month ** Jiffy Lube policy, for absolutely no reason....I never got that 3 month thing. To me it equates to putting new tires on your car every 10,000 miles or 1 year whichever comes first, just because. If the tires aren't worn, then don't replace them.

Can you imagine if the tire industry had ever started a hoax that your tires needed to be replaced every 10K miles, because the molecular structure of the rubber breaks down internally, even though you can't see it. I guarantee there would still be people putting new rubber on their vehicles every 8K...just to be on the safe side, before they hit 10K. I have friends who's father's still change their spark plugs every 8-10K, even though their plugs will be good for 3 times that long at a minimum, of course they still call them "ignitors", so it's not that unexpected. Creatures of habit is what it comes down to.....and brainwashing.

 

[Arctic388]

i started using AMSOIL and will leave it in till my mileage suffers. i've known people who use Fram and never change their oil, just doesnt let it get off the dipstick. not in the hatch marks just where it will show on the tip and the cars are still going for years. so i know a good oil will last a long time. a lot of good people are just helping a lot of foreigners stay rich and keeping everyone else paying higher fuel bills. just say everyone changed their oil at 7500 miles instead of 3000 think of the difference it would make on the cost of crude. and 99% of the time it wouldnt be any ill effects to run that long or longer. even on dino. just my 2 cents

 

[jbas]

LOL at this ever-continuous discussion!

Why don't we all just rig a by-pass filter system into each of our vehicles and maybe we won't ever need to change the oil - just the filters and an oil top-off? Drill the Alaska Refuge & off-shore Kal-y-forn-e-ah and the Gulf, and tell Kuwait, Iraq, Iran, and all the Arabians to go !!&^%$#! themselves.

 

[mmcpeck]

Very well said jbas, I couldn't agree more. The price of taking extra environmental precautions to keep these areas clean, is better than the cost of paying foreign countries for oil and worth it.

 

[pitzel]

quote:

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"Has anyone asked the question, why is synthetic oil going up in cost relative to the cost of the crude oil barrel cost? Why would it ever get to $15.00 per qt?"

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Synthetic oil is primarily derived from natural gas.

$2.49 M1 was probably from an era of $20/barrel oil and $2 natural gas. NYMEX is showing ~$64 and $7 tonight respectively, and those prices have come down quite a bit.

If these prices are the result of a warm winter, and the slow demand season of spring, then this summer is going to be very, very interesting.