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Oil. Yeah, really, oil.


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Why so stinkin' much, to begin with? Seriously, what prevents engineers from designing an engine that uses a tenth the oil?

 

Next, we all see the lab results... most oil is still perfectly good when it reaches the specified change interval... why do manufacturers recommend (require for warranty, more or less) such conservative change intervals, particularly the time intervals? What happens to oil sitting in an engine that doesn't happen in a plastic jug?

 

 

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Francois_Dumas

There was a research and published report quite a few years ago by a Dutch engineer, showing that a car (Volvo I believe) did not need ANY oil change over his life time of many 100's of 1000's of kilometers.it was fiercely contested (on tv) by the car manufacturers and oil companies..... obviously.

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Joe Frickin' Friday
Why so stinkin' much, to begin with? Seriously, what prevents engineers from designing an engine that uses a tenth the oil?

 

Next, we all see the lab results... most oil is still perfectly good when it reaches the specified change interval... why do manufacturers recommend (require for warranty, more or less) such conservative change intervals, particularly the time intervals? What happens to oil sitting in an engine that doesn't happen in a plastic jug?

 

Some thoughts and speculation here, not guaranteed to be correct.

 

At the root of it, I think, is the idea that car manufacturers really want to avoid having a customer's car fail prematurely, because it damages that manufacturer's reputation. Suppose for example you have two manufacturers making cars that are virtually identical - but Manufacturer "A" says "change your oil every 12,000 miles/2 years," and Manufacturer "B" says "change your oil every 6,000 miles/1 year." Over a very large number of vehicles (e.g. Honda sells about 300K Civics per year), a longer change interval means Manufacturer "A" is going to get a few extra engine failures. A lot of car prospective car buyers pay attention to brand/model reliability, but almost nobody, when test-driving a car, asks how often they would need to change the oil. So it's in a manufacturer's interest to err on the conservative side when it comes to specifying change interval (though they won't be as ridiculous as Jiffy Lube or your dealer, both of whom have a financial interest in convincing you to let them change your oil as often as possible). This is especially true for customers who should (but don't) utilize the "harsh duty" oil change interval specified in the manual. I confess to being one of them: my car's owner manual says to change the oil every 7500 miles if I mostly drive long trips in warm weather, or 3750 if I drive a lot of short trips and/or drive much in cold weather. Well, this is Michigan, and my commute is about 4 miles. Not so good for the engine. But I still only change the oil once every 6000 miles. Not too worried: my second-to-last car had 110K miles on it when I sold it, and the engine was doing fine.

 

There's also the fact that individual cars of the same model do vary, but the manufacturer only gets to put out one very simple set of instructions for everyone. Maybe one car has an engine with good piston rings and minimal blow-by, so the oil doesn't get very contaminated at all, and it can go for 10,000-15,000 miles between changes without any issues. Maybe another car has scored bores and coked-up rings, with a lot of blow-by that results in heavy oil contamination, and the oil in that engine isn't going to be able to do its job very well past, say, 8,000 miles. If everybody changes their oil at 7,000 miles, they'll both be fine.

 

Regarding the time-based oil change specification (e.g. "change oil at least once per year"):

Most cars don't sit around much. It's pretty uncommon for a typical passenger car to drive less than ~6000 miles in a year (this doesn't include oddballs like vintage/collector cars or track cars). Some people are boneheads about paying attention to mileage intervals, so maybe it's easier to just remind them to just do annual maintenance (including oil change). Also, compared to oil sitting in a plastic jug, oil sitting in an engine has been contaminated with combustion products. It may be that residence time matters when trying to keep that stuff from eating away at engine parts and/or compromising the positive characteristics of the oil.

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Over-the-road trucks and other heavy duty equipment often use procedures that greatly extend oil change intervals. This is an example from Cummins which provides for 80,000 miles between complete oil changes. After market kits/procedures are available from a variety of companies. I periodically have my diesel truck's oil analyzed by Blackstone Laboratories. I've had good reports come back with a recommendation that I could extend my oil change intervals well beyond the 7,500 miles I generally use.

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Been out of the car business for several years now.....but I cannot remember seeing an engine being replaced due to oil failure. I don't doubt there were a couple from owners that didn't realize oil needed changed. But the truth is as long as you keep the oil level correct they will go an unreal distance without failure.

 

Over the road trucks use bypass filtering systems. You change the filters at the recommended interval, add enough makeup oil to put the level to the correct amount. This "new" oil contains enough additives to make up for what wears out during use. These bypass filters are very good at removing contaminants. 500,000 miles before doing a complete oil change is common.

 

There is little doubt we waste oil in cars and trucks and bikes. A really high tech filter system with monitors for excessive fuel or other contaminants could conceivably allow 100,000 mile oil change intervals. I am in for that! Surprised some company is not doing that. Think what the first "maintenance free" car would do for sales!

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Joe Frickin' Friday
Over-the-road trucks and other heavy duty equipment often use procedures that greatly extend oil change intervals. This is an example from Cummins which provides for 80,000 miles between complete oil changes.

 

Some key differences for big-rigs:

 

#1: cold-starts are the most detrimental thing for oil. That's when pistons/rings/bores aren't warmed up to their normal fit, and so blow-by is greatest. Big-rigs tend to drive very long distances between cold starts. If (for example) they go 150 miles between starts, then 80,000 miles only represents 533 starts (and many of those may be warm starts rather than true cold-starts). Me? If I drive to work, drive to lunch, and drive home, that's 1000 cold starts in one year, not including grocery shopping, road trips, miscellaneous errands. If I go four miles between starts, that's 1500 starts every 6,000 miles.

 

#2: big-rigs don't use quarts of oil, they use gallons. A typical oil change for a heavy-duty diesel engine requires around ten gallons of oil. That's a whole lot of additives in there, plenty to cope with tens of thousands of miles of operation.

 

And in the case of the Cummins program you mentioned, they are specifically analyzing the operators' oil so they can tailor the change interval. Fleet operators are willing to go to the trouble of submitting samples for such analysis because there's big bucks involved: if you own ten trucks, and you can stretch the oil change interval from 50K out to 80K, you reduce your maintenance costs ($300-$400 per oil change), and you reduce the amount of time that each truck is out of commission (i.e. not out on the road earning money) for oil changes. OTOH, if you're the owner of one car, trying to see if you can stretch your oil change interval from 7500 miles to 10,000 miles? Much less incentive to put up with the cost and hassle of oil analysis; easier to just follow the owner's manual and get on with your day.

 

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I served in the mechanized infantry for more than 20 years. Our Bradley fighting vehicles had a Cummins VT903 V8 diesel. The engines idled for hours on end, went through numerous cold starts while sitting in the motor pool, and ran flat out most of the time when we were training. We never had issues with the Cummins, they always would start and run.

 

At the time, the Army had an extensive oil analysis program, we pulled samples monthly on the transmissions and engines. I only remember changing oil once or twice on the engines. We also changed a few engines and transmissions based on the oil analysis. We used 15w40 conventional oil in everything, transmission, final drives, wheel hubs, and engine.

 

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Over-the-road trucks and other heavy duty equipment often use procedures that greatly extend oil change intervals. This is an example from Cummins which provides for 80,000 miles between complete oil changes.

 

Some key differences for big-rigs:

 

#1: cold-starts are the most detrimental thing for oil. That's when pistons/rings/bores aren't warmed up to their normal fit, and so blow-by is greatest. Big-rigs tend to drive very long distances between cold starts. If (for example) they go 150 miles between starts, then 80,000 miles only represents 533 starts (and many of those may be warm starts rather than true cold-starts). Me? If I drive to work, drive to lunch, and drive home, that's 1000 cold starts in one year, not including grocery shopping, road trips, miscellaneous errands. If I go four miles between starts, that's 1500 starts every 6,000 miles.

 

#2: big-rigs don't use quarts of oil, they use gallons. A typical oil change for a heavy-duty diesel engine requires around ten gallons of oil. That's a whole lot of additives in there, plenty to cope with tens of thousands of miles of operation.

 

And in the case of the Cummins program you mentioned, they are specifically analyzing the operators' oil so they can tailor the change interval. Fleet operators are willing to go to the trouble of submitting samples for such analysis because there's big bucks involved: if you own ten trucks, and you can stretch the oil change interval from 50K out to 80K, you reduce your maintenance costs ($300-$400 per oil change), and you reduce the amount of time that each truck is out of commission (i.e. not out on the road earning money) for oil changes. OTOH, if you're the owner of one car, trying to see if you can stretch your oil change interval from 7500 miles to 10,000 miles? Much less incentive to put up with the cost and hassle of oil analysis; easier to just follow the owner's manual and get on with your day.

 

 

All true. Even the main oil filter on our Volvo tanker truck took a gallon of oil which made for great fun trying to hold it up to get it started onto the filter mount. I have mine analyzed because diesel can contaminate the oil due to the design of the LB7 Duramax where the injectors are under the valve covers.

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Friends I met in '79 had a early Corolla with high mileage.

Found out they never changed the oil.

Just added "as needed".

Well into 6 figure mileage at that time and they drove it for years, and years. :dopeslap:

 

I've seen mc oil problems from waayy too much.

I've seen mc problems from waayy too little.

Some leak oil.

Some burn oil.

Some blow oil into places they shouldn't.

 

$ince it i$ my money, I change my truck oil every 5,000 mile$.

It could probably do 15-20,000 easily.

Wonder what happens around the world wrt clunkers?

 

 

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Price at all 4 of the BMW dealers in the greater DC area charge around $160 - $170 for a simple oil change! I change oil myself, however, because of possible warranty issues, I have been advised to use only the BMW specific oil. Had to buy 4 liters of BMW's 5W-40 Advantec Ultimate oil @ $17.00 per liter for my '18 GSA. Also found out, since I do not own a GS-911 device, I can can not reset the bike's computer without paying the dealer their minimum labor charge of .2 hours to reset it. :(

 

Also, I did not see until I returned home from purchasing the oil, at a BMW dealership, that the receipt for the oil listed it as: "JMA BM-7.P Dimple Shell" - whatever that means? The salesman did mention that the BMW oil is made for them by Shell.

Edited by Endobobdds
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Price at all 4 of the BMW dealers in the greater DC area charge around $160 - $170 for a simple oil change! I change oil myself, however, because of possible warranty issues, I have been advised to use only the BMW specific oil. Had to buy 4 liters of BMW's 5W-40 Advantec Ultimate oil @ $17.00 per liter for my '18 GSA. Also found out, since I do not own a GS-911 device, I can can not reset the bike's computer without paying the dealer their minimum labor charge of .2 hours to reset it. :(

 

Also, I did not see until I returned home from purchasing the oil, at a BMW dealership, that the receipt for the oil listed it as: "JMA BM-7.P Dimple Shell" - whatever that means? The salesman did mention that the BMW oil is made for them by Shell.

 

My HP4 is still under warranty and I do the changes myself with Rotella T6 (less than $50 with filter and my hourly rate). The bike computer still states that it needs a service, but I don't worry so much about that as it's simply time/mile based anyway (No GS911 either). I keep my records pretty good ok and know when I need to change oil. Besides, if the engine fails, the burden of proof is on the company to state that what I did to the bike caused the failure.........I'll take those chances.

Edited by Living the Dream
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Lone_RT_rider
Driving a 2016 Town and Country. Oil change light comes on between 7 and 9 thousand miles.

 

Bud, on a Chrysler isn't that known as the "low oil" light?

 

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I have about 1% of the engineering expertise that Mitch, Terry, DR and others have on this site...and that is if I am having a good day. I'll share some anecdotal information. I think Ive shared a couple of these stories here before. Growing up, my Dad owned a Chevrolet and a Ford dealership. I always had an interest in cars and things mechanical. Since I wasn't the greatest teenager in the world, when I wasn't in school or after sports practice, my parents made me go to my dad's dealership nearly everyday from grade school and by my desire through college.

 

I can't tell you how many hundreds if not thousands of cars changed oil/filters on. By the time I was about 12 I had an interest and learned how to overhaul transmission and engines. I think I could still do a small block chevy and powerglide in my sleep.

 

Oil changes....we had engine failures. Rod's thrown occasionally, lifters banging so loud even tightening them down didn't help. We would open them up to repair them. There were those engines that were nearly spotless on the inside with very clean oil channels and there were those engines who were sludgy to very sludgy with clogged channels and always uneven oiling...……… What they had in common was frequency of oil changed and how long they were driven when they were driven. I remember one of the GM schools I went to where the engineers (folks like Mitch) explained that the death of oil and engines was short runs. Something I never forgot (whether true or not) was the 327 top engineer telling us unless you got the oil up to 180 degrees for at least an hour when you drove it, it would actually eventually trash the engine due to not burning off moisture, acids, and other contaminants. Does that apply to modern cars and motorcycles...not a clue.

 

 

I'll tell you one thing that led to more sludge and spun crank bearings was an additive that was very thick (wont say name here) and was marketed as stopping oil burn and prolonging life.....

 

Remind me someday and I'll tell you about the lady who drove her 1964 Chevy Impala in for it's first oil change in 1977. I asked her what oil she used...she said what ever it came with that's what's in it now.....Too long for here.

 

Cheers.

 

Edited by Skywagon
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I was looking at riding mowers last week. Some John Deere models now come with a big screw on oil filter pre-loaded with all the oil. Just unscrew the filter, swap it out, and voila! You've changed the oil. Neat idea, but the filters are $40!

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Why so stinkin' much, to begin with? Seriously, what prevents engineers from designing a vehicle that uses no oil?

Fixed it for you.

 

18k ZERO oil miles since May 2017 :thumbsup:

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Driving a 2016 Town and Country. Oil change light comes on between 7 and 9 thousand miles.

 

Bud, on a Chrysler isn't that known as the "low oil" light?

 

Nope. Oil change due indicator. Level is not low. Once changed, the indicator needs to be reset.

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