How come gas vehicle engines don't burn oil?

[fried1765]

It's still around. Try Walmart.

We used it to polish things years ago. It's just powdered stone dust and I think that's all other cleansers are as well. I can't imagine it on cylinder walls but I used to put STP in my shocks to reduce leaking and couldn't imagine that either.

If you're a kid and have the time and desire, a little Bon Ami or other cleanser on a wet rag will polish up a smooth river pebble into a shiny gemstone.

Much more easily done in a cheap Chinese electric tumbler.

 

[jaxs]

Reminds me of the old Vega oil burners............

Actually, all internal combustion engines 'consume' oil, it's just the amount is so small in a modern engine that you won't notice the drop on a dipstick but they all do none the less.

GM was too cheap to do what everyone else knew had to be done to cast an aluminum block. Porsche, Mercedes-Benz, the Japanese, everyone knew electric heaters were required inside the cylinders to slow the cooling and control the metallurgy of the formed grains. Done right produces a superior cylinder.

Don't knock the little fellers. One of the best home runs I ever scored was a Vega of all things. Car was abandoned after a body shop put a paint job on it. Shop owner gained title but couldn't get any bits because of Vega's reputation. Body shop offed to sell it to me for what he spent for material to paint it. so I went to look. Raised the hood and there sat a race preped Cosworth.:applause::number1::jump: After taking it for a joy ride, I made a killing on resale. Always wondered how and why someone left it there but fully understand why noone wanted any part of a Vega.

 

[SPYDERLK]

I would like to know which brands don't use oil between changes cause the last two I have owned sure did..
I still own the Hyundai

I think the magic is precise cylindrical bores and well seated rings. I had a 750cc Honda Sabre and an ST 1100 that both used less than an ounce per thousand miles until they were above 20K mi. These are spirited hi revving engines running at 3 or 4 Krpm on highway and seeing 8 to 11Krpm at least daily. Combine the good ring seal and cylinder wall wiping with the very brief flame events and the oil film on the walls is essentially unaffected. The cyl walls are "cool" and the flame of combustion, occurring for about 30 mS at 1Krpm (1/2 of 60sec/1000) every other revolution, cannot even reach the the wall. - - Think about flicking a propane torch across a 200F piece of oiled steel. - - At higher rpm the exposure is proportionally more brief. The only oil "burned" is that that escapes ring control and becomes stagnant above the inherent auto refresh of the ring path.

Dyno lab mech engineer here. We run a lot of oil consumption tests.

All engines burn some oil. No set of piston rings is able to scrape 100% of the oil of the cylinder walls on the downstroke. You wouldn't really want that, anyway. Then how would the rings be well lubricated for the return upstroke? Oil consumption is a known engine design consideration. Most OEs target around 10,000 miles per quart nowadays.

So why don't you notice that on the dipstick? Well, either you're not paying real close attention, most likely, and it's still in the "normal range" on the stick. No problem. More likely, some of the oil that has been burned away has been replaced in volume with combustion byproducts (soot and un-burned or partially burned hydrocarbons), and especially in direct-injected turbocharged engines, raw gasoline. It sneaks past the rings down into the crankcase from cylinder pressure, or gets scraped down if left on the cylinder walls during the power stroke. We call this "fuel dilution", and it can get as high as ~10%. Meaning, 10% of the oil you drain out during a change is actually mixed-in gasoline. Diesel engines do this also.

All engines burn oil. They have to. If you don't notice it, or it seems like zero consumption, great!

Wow. That much fuel dilution by gas would be horrible.

Likewise, my 2005 Ford Focus Wagon. 150k miles now, and its still full or real close to it on the stick, and nearly clean in color, at the 10,000 mile oil changes I learned were specified for this engine in Europe. Much of my miles are the 100 miles each way between home and ranch at near constant speed, a 'light use' application.

For several cars over the last 30 years I've followed the rule of change the oil when it's down a quart, so intervals of 4 to 9 k miles. All have run until sold at over 125k miles without much increase in consumption. I use semi-synthetic oil, Motorcraft, Castrol etc. I believe in the theory that most engine wear occurs at a cold start, not on the highway.

Modern cars are completely different than what most of us learned on. One example is much better air cleaners which reduce cylinder wear. And of course, far better oil is specified today. I think oil-related engine failure is mostly a thing of the past, now.

:thumbsup: Your oil stays in good shape. My bikes shared their oil with the transmission and thus it degraded fairly quickly. I needed to change my oil more often, ~ 4Kmi, or the consumption increased quite noticeably.

Have heard of Bonami dumped into the engine intake to "hone" the cylinder walls. Bonami was a powdered abrasive household cleanser. Don't know if it's still made.

I heard that too and nearly destroyed my Sabre engine by trying that trick at about 50Kmi. - - Definite loss of performance and increased oil consumption.

Years ago,, Honing typically created cross hatching in the cylinder wall that help to retain a miniscule amount of oil on the walls and since it is cross helps in retaining oil by the rings. It also allowed the rings to seat more easily. Today machining techniques hold tolerances significantly tighter than 50 years ago... provided it is done correctly.
[[ Bonami would create slight verticle scratch honing that would allow both oil and compression to seap by. ]]

My experience says youre probably right.

 

[BravoXray]

Have heard of Bonami dumped into the engine intake to "hone" the cylinder walls. Bonami was a powdered abrasive household cleanser. Don't know if it's still made.

My dad tried that on a DT466 in his IH1850 trailer toter years ago. It would slow down the oil consumption for a while, but then it would start using quite a bit again. One day he dosed it with too much BonAmi. It got by the rings and into the oil. We had to overhaul it and anything that oil lubricated was worn.
Liners, pistons, cam, rocker arms and shaft, turbo, oil pump, oil cooler, wrist pin bushings, and air compressor were replaced, crank was turned .010" under.
A little works for a while, sometimes, but too much will total the engine.

 

[5030]

My dad tried that on a DT466 in his IH1850 trailer toter years ago. It would slow down the oil consumption for a while, but then it would start using quite a bit again. One day he dosed it with too much BonAmi. It got by the rings and into the oil. We had to overhaul it and anything that oil lubricated was worn.
Liners, pistons, cam, rocker arms and shaft, turbo, oil pump, oil cooler, wrist pin bushings, and air compressor were replaced, crank was turned .010" under.
A little works for a while, sometimes, but too much will total the engine.

Just a pinch between the cheek and gum so to speak.

Really only works on a 2 stroke Detroit Diesel.

 

[sld]

Oil manufacturers make a difference to the amount of oil burned. Made the mistake of trying mobil 1 for diesels in my 2012 TDI Passat. For that 10000 mile change it burned almost a quart. Changed back to the dealer sold Castrol and went back to burning no oil between changes. Go figure.

I had that happen too. I don't think it was burning though. I have read where Mobil 1 uses a lot of thinners that are volatile and will actually flash off or evaporate.

 

[California]

One day he dosed it with too much BonAmi. It got by the rings and into the oil. We had to overhaul it and anything that oil lubricated was worn.

That reminded me of an old Mercedes I bought for $100 with a rattle, not knock, in the engine. I discovered the timing chain, like bicycle chain, had lost some hardened steel rollers and the pulverized steel had scoured everything that oil touched. Total loss. I re-sold it.

 

[Oaktree]

Used to be engine oil losses were common, but when the Japanese cars hit the American markets and were quite successful in sales based on their high reliability, nearly all automotive manufacturers around the world tightened up their machining standards, and so tolerance gaps between piston rings and wall are now so close, no oil is burned. Now it's not uncommon to see Toyota cars going 500,000 miles these days, and lots of American made cars can also do those longevity miles. Back in the 60's any car getting 100k miles, was ready for an engine rebuild or the junkyard.

I don't think so. While the Japanese often had better initial fit and finish over American vehicles in the 70s, longevity wasn't their strong suit. Back in the 80s a co-worker had a Honda with ~70k on it, and it burned some ridiculous amount of oil. From what he was able to find out, that was pretty common. I also take the half million mile toyota myth with a grain of salt too...not saying that some extremely well-maintained ones get there, but I've never seen one that even came close.

Of course, here in New England rust has always been the determining factor on how long a vehicle lasts, and those Japanese cars of that era rusted like a brillo pad.

The best explanation for that is: It was a Chrysler product:laughing:!

Only Chrysler product I've ever had that was an oil burner was a Caravan with a Mitsubishi engine in it.

 

[Grumpycat]

I don't think so. While the Japanese often had better initial fit and finish over American vehicles in the 70s, longevity wasn't their strong suit. Back in the 80s a co-worker had a Honda with ~70k on it, and it burned some ridiculous amount of oil. From what he was able to find out, that was pretty common. I also take the half million mile toyota myth with a grain of salt too...not saying that some extremely well-maintained ones get there, but I've never seen one that even came close.
.

Co-worker commuted 100 miles/day in a 1992 Toyota 4WD pickup, 3.0L V6 5 speed. Factory lifted mini-monster truck. Gave it to his nephew at 450,000 miles in excellent running order. Recall replaced cylinder head gaskets at 160,000. Fuel pump soft-failed like clockwork every 110,000. Several new windshields due to rock hits. Drove 70 MPH in 4th gear pulling 3800 pound boat and trailer because he found that got 2 MPG better than 5th.

 

[rademamj1]

I don't think so. While the Japanese often had better initial fit and finish over American vehicles in the 70s, longevity wasn't their strong suit. Back in the 80s a co-worker had a Honda with ~70k on it, and it burned some ridiculous amount of oil. From what he was able to find out, that was pretty common. I also take the half million mile toyota myth with a grain of salt too...not saying that some extremely well-maintained ones get there, but I've never seen one that even came close.

There is a lot more cars over 500k miles than you may think. I have seen at least nine Toyota vehicles with over 500,000 miles on them this summer, on used car lots in Dallas. Some of them look in very good condition for the mileage. But my son was not interested in any of them for his first car. I talked with one used car dealer, and he said 60% of cars just don't make past 15 years because of accidents.

A check on Cars.com showed 17 Toyota's, 2 Honda's and 8 Fords have over 500k.