110,000 miles and never changed oil

[TC]

"If you add a quart of oil every 500 miles and your car holds 4 quarts, then you have technically "changed" your oil every 2000 miles."

Not exactly... You've actually DILUTED (rather than "CHANGED") the old oil mix every 500 miles, but never fully removed the accumulated contaminants at any given time. One possible ramification of this is that, when 100% new oil is refilled at any given time, one would experience a period of heightened cleaning effect (a new, uncompromised detergent/dispersant package) which the "add a quart" engine would never experience. But yes, in some engines (certainly a forgiving engine like a 60's Chrysler Slant 6), the two scenarios might end up being a "six of one, half-a-dozen of another" thing.

[ December 15, 2004, 01:57 AM: Message edited by: TC ]

 

[1sttruck]

On friction, it's also been noted that some effective anti-wear films can result in more friction, so one needs to be careful when making statements about oil analysis, wear, and friction. Also, based on some tests and a survey of some literature:

http://www.ornl.gov/~webworks/cppr/y2001/rpt/101808.pdf

3.2 Recommendations
Based on a literature review and consideration of issues raised in discussions with colleagues, there seems to be an opportunity to aid the diesel and automotive engine development community in the area of testing standardization and the use of degraded oils in laboratory tests.
(1) Develop a new standard test procedure based on the current ASTM G-133 reciprocating test, but that uses ring and liner segments with degraded (or simulated degraded) oil under repeated cold start conditions.
(2) Formulate a basic lubricant composition that produces the effects of degraded oil when using standardized testing procedures. This may require such approaches as ‘cooking the oil’ and adding abrasives to simulate the effects of carbon soot on the removal of anti-wear additives.

 

[oilpan49]

You know, it's stories like these that make me be all, *** !?!??!?

Just to throw in another one of these "never change my oil in x years stories"

Older guy who lives down the road from me has a 1987 Ford Ranger with a 2.3L 4banger. It's white, and it's ugly ok. I remember when I was younger the guy bought it brand spankin new. Since then he has never and I do mean never changed the oil since 1987 and today 17 years and 115K later, it's still running. All he does is top off with Pennzoil 10w30. Ok, I somewhat believe him but also I have never seen him changed the oil before unless he takes it somewhere or does it at 3AM when I'm sleeping so I don't see it, lol!

I wonder about stories like this. I would never do something like that to my Ranger or any vehicle I would own. I have more respect for vehicles than that,,,,,,,AR

 

[MGBV8]

Heat activated additives also contribute to virgin motor oil be less lubricious until they have been in use for a few heat cycles.

Terry,

If running an ester based oil, are the esters not providing this protection, in addition to helping prevent wear on start up at engine temps below 60c.

 

[mikemc]

These stories remind me of folks who refuse to wear seat belts and use a story of some freak accident as 'proof' to back up their decision. I'll go with the odds, thank you. I wear my seat belt and I change my oil!

 

[Mystic]

It seems like these 100,000 miles on one oil change stories never die. Even if a car or truck could be driven 100,000 miles on one oil change-what would be the point? Replacing an engine nowadays is something like a 3000 dollar or more project. Oil at $1.50 a quart and a $2.00 oil filter every 3000-6000 miles seems to me a lot cheaper.

My Dad was a mechanic (a good one-he could fix anything) and he taught me the importance of oil changes. I would not try to go 100,000 miles on one oil change of Amsoil, much less a conventional motor oil.

 

[pitzel]

quote:

---

Originally posted by Mystic:
It seems like these 100,000 miles on one oil change stories never die. Even if a car or truck could be driven 100,000 miles on one oil change-what would be the point? Replacing an engine nowadays is something like a 3000 dollar or more project. Oil at $1.50 a quart and a $2.00 oil filter every 3000-6000 miles seems to me a lot cheaper.

My Dad was a mechanic (a good one-he could fix anything) and he taught me the importance of oil changes. I would not try to go 100,000 miles on one oil change of Amsoil, much less a conventional motor oil.

---

Well now you're questioning the entire raison d'étre of these forums when you pose a question such as the one above.

In the world of maintenance engineering, we generally end up using the concept of net present value (NPV) to evaluate levels of maintenance, and we utilize models that attempt to show the sensitivity of NPV as a function of the application of different maintenance strategies on a piece of equipment.

Changing oil every 3000 miles as an arbitrary rule is very costly when a particular lubricant can last 25,000, if not 50,000 miles before it needs to be changed. An oil change not only requires significant labour and materials, but also requires a piece of equipment to be out of service for a length of time, with corresponding losses in terms of production from that equipment.

For an individual, a 3000 mile oil change versus a 10k mile oil change might give an engine 400k miles instead of 360k miles. 40 oil changes versus 133 oil changes. If you value each oil change at $20 (the oil, miscellaneous supplies, the cost of fuel associated with oil disposal, etc.), the difference amounts to $2700. If you amortize that over 10 years of operation, at a discount rate of 10%, that's approximately $4350.

$4350 goes a long, long, long ways towards a replacement engine. I don't think you can find many 10-year-old vehicles that you couldn't have the engine replaced with a much lower time one for $4350. Money in my pocket is 'cheap insurance', not wasteful use of motor oil.

(if you run the numbers for 20 years, 20k miles a year, you would have $8000 savings in the example above. 30 years, $22000 -- woah, that's almost half the cost of a good car, just by not falling victim to the 3k mile oil change myth -- and who wants to drive a 30 year old, inefficient gas guzzling car anyways???)

[ December 18, 2004, 04:37 AM: Message edited by: pitzel ]

 

[Mystic]

If you buy a new car today and it costs $20,000 dollars, how much do you think a replacment engine for that car will cost ten or twenty years from now? And how much will a new car or truck cost ten or twenty years from now?

If you do the oil changes yourself you can change oil in many vehicles for about ten bucks. Four oil changes a year are fourty bucks. In ten years that is $400.00. It is $800.00 in twenty years.

Price a rebuilt or remanufactured engine-today. How much will such an engine cost ten or twenty years from now?

I will change the oil and oil filter.

 

[Mystic]

A few other things to keep in mind. Higher licensing costs for a new vehicle. Higher insurance costs. More depreciation. Even if the old car uses more gasoline, the owner is not making payments on a new car and not spending a lot of money in other areas. The guy who owns the twenty year old car that still runs great is almost driving free compared to the guy making the huge car payments, licensing costs, insurance, etc.

 

[pitzel]

quote:

---

Originally posted by Mystic:
If you buy a new car today and it costs $20,000 dollars, how much do you think a replacment engine for that car will cost ten or twenty years from now? And how much will a new car or truck cost ten or twenty years from now?

If you do the oil changes yourself you can change oil in many vehicles for about ten bucks. Four oil changes a year are fourty bucks. In ten years that is $400.00. It is $800.00 in twenty years.

Price a rebuilt or remanufactured engine-today. How much will such an engine cost ten or twenty years from now?

I will change the oil and oil filter.

---

Yes, but in my analysis I totally neglected any inflationary effects of the cost of oil. Do you really think that the cost of oil will be $1.50/quart 5 years from now? 10 years from now?

What is your *actual* cost of acquiring the oil to do your oil changes. Don't just include the cost you pay at Wal-Mart. Also add in the cost of fuel to get to Wal-Mart, the cost of operating your vehicle, the cost of those extra trinkets you end up buying unnecessarily, the cost of shop towels, cleaners, rags, the costs of extra laundry due to oil-laden clothing. And then, isn't your time worth at least something?

I think $20 is actually very conservative once you factor in all those factors (not including the cost of time). Plus people who perform excessive 3k mile OCI's also tend to perform extremely excessive filter changes, which makes the economics even worse.

Also, in your $800 calculation, you have failed to take into account the concept of 'time value of money'. A dollar saved today is worth more than a dollar saved tomorrow, is worth more than a dollar saved five years from now. The discount rate I chose was based on the average return of the S&P 500 USA stock index over the past 60 or 70 years. Put the money you save from not doing excessive OCI's into a low-MER index fund or ETF for best results.

As for your question of rebuilds, call a couple junkyards and price out engines pulled from wrecks, 10-year old engines. Chances are, they aren't going to cost you a lot of money. The engines being built today, being installed in cars today, *will* be available for similar costs, plus inflation, 10 years from now, from the junkyards. Go price out a 10-year-old junkyard engine today, and multiply by 1.35 to get what a built-in-2004 engine will probably cost 10 years from now (3% inflation). $2000 buys a lot of 1994-built junkyard engine today, $2600 will buy you a 2004-built junkyard engine in similar condition 10 years from now.

 

[pitzel]

quote:

---

Originally posted by pitzel:
What is your *actual* cost of acquiring the oil to do your oil changes. Don't just include the cost you pay at Wal-Mart. Also add in the cost of fuel to get to Wal-Mart, the cost of operating your vehicle, the cost of those extra

---

Oh yes, and also repeat this cycle of costs, in reverse, albeit less often, for the disposal of the excess used oil legally. I have yet to hear of a BITOG member that has curbside pickup for proper disposal/recycling of used oil.

Yet another consideration is the actual probability of being able to 'recover' your investment in extra oil changes over the life of the car. What good are 3000 mile oil changes when your insurance company offers you next to nothing (rightly so) on your 15-year-old wreck that was in an accident and beyond reasonable repair? Suddenly you find yourself regretting the sheer excess of 3000 mile oil changes even more. Thats why I say, friend, 'cheap insurance' means money in my pocket, not excessive amounts of oil wasted in my crankcase.

Same situation applies to cars that become victims of cancer. How many 20-year-old cars end up being scrapped with perfectly good engines underneath their bonnets simply because their bodies are no longer serviceable?

[ December 18, 2004, 06:06 AM: Message edited by: pitzel ]

 

[MGBV8]

I confess to driving 30 year old cars with cheap insurance and tax but gas guzzling,with the intention of avoiding scrapheap.

Therefore looking for most cost effective way of reducing wear with carb fuelling, short journeys, and cheap filters.

Any recommendations?