I see a lot of comments on this site how modern engines are machined to such good clearances and tolerances that you hardly even need to worry about breaking them in. Then I see comments that Ford and other manufacturers allow up to a quart of oil consumption in 1000 miles as normal. The two seem very contradictory. If the engines are built to such great standards, why do some consume so much oil? Friday effect?
Normal Oil Consumption and Modern Machining
- Thread starter TallPaul
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Excellent question. Especially with robot built engines that remove any chance of the Friday or Monday hangover effect, we could only blame oil usage or oil sludge related problems on either faulty design or usage that does not meet the use anticipated by the designer.
Now we could also insert the argument that the rush to meet fuel savings requirments and to appease environmental concerns by pushing thinner oils and longer intervals may be part of the equation in some instances, such as a back spec to 5w20 and then a reversal back to 5w30, as we have seen in a few instances.
Don't get me wrong, i'm all for 5w20 oils, but not across the board in vehicles that may not have been tested thoroughly.
Now we could also insert the argument that the rush to meet fuel savings requirments and to appease environmental concerns by pushing thinner oils and longer intervals may be part of the equation in some instances, such as a back spec to 5w20 and then a reversal back to 5w30, as we have seen in a few instances.
Don't get me wrong, i'm all for 5w20 oils, but not across the board in vehicles that may not have been tested thoroughly.
awesome question....i'm sure this thread will get a bit heated LOL...
My F150, i go back and forth between 5W-20 and 30...settled on 20...for now.
My F150, i go back and forth between 5W-20 and 30...settled on 20...for now.
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During prolonged high-speed driving, when driving in the mountains, or when towing a boat, oil consumption can double or even triple. The 1 quart or liter limit seems high, because it is the upper limit. So what?
I think some have experienced this high consumption without prolonged high-speed driving, driving in the mountains, or towing.
The reason such high oil consumption is "normal" is because the manufacturers don't want to have to fix the engine under warranty, pure and simple.
In the "old" days this was true. Anything greater or equal to 1qt/1K was acceptable. I don't know if it still applies.
To an early SC/SL Saturn owner 1K or more is nirvana.
To an early SC/SL Saturn owner 1K or more is nirvana.
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Then it's time to take care of what needs to be fixed, for example valve stem seals.
Would you prefer "If oil consumption exceeds 125 ml per 1000 km of light duty driving, the engine needs to be overhauled"?
I don't have any HARD data, but my experience has been that GM engines are a "looser" fit which allows them to spin freer, giving better fuel milage, at the slight expense of a quart of oil every 1500 miles or so. I'm confident that many on this board can back me up on this and I'm sure thats a corporate decision. I had a Ford that consumed ZERO oil, but everything else FAILED pre-maturely? Currently have several Toyotas that perform flawlessly with ZERO consumption of anything. That sentence that says "a quart every 1,000 miles is normal" does ROT me though! It spells out - WE MAY MAKE JUNK FROM TIME TO TIME - and you're just goona have to live with it SUCKAAH! Tall Paul, don't go hard on me for the Toyota thing as I see you're from the MOTOR CITY, thats just been my experience...
The only car i've ever had that used a regular amount of oil that was, in my opinion, excessive, was a 1977 GMC van with the GM 350 V8.
It used almost no oil around town but on the hwy it would go through about 1 qrt every 500 miles. Of course there was no mystery where it was going, the right rear plug would have to be changed at every oil change or that cylender would begin to drop. I'm guessing failed rings on that piston.
It was still a great van though and fun to drive. We just kept a case of Pennzoil 10w40 in the back!
Granted this was not a "new" van though, it only developed after about 60,000 miles.
If i had a new car that developed serious oil usage problems within warranty i would be very unhappy and want to get it fixed.
My old accord used approx 1 qrt every 3000 miles which i felt was acceptable considering it had well over 100K miles on it and was driven, how should we say, VERY hard.
It used almost no oil around town but on the hwy it would go through about 1 qrt every 500 miles. Of course there was no mystery where it was going, the right rear plug would have to be changed at every oil change or that cylender would begin to drop. I'm guessing failed rings on that piston.
It was still a great van though and fun to drive. We just kept a case of Pennzoil 10w40 in the back!
If i had a new car that developed serious oil usage problems within warranty i would be very unhappy and want to get it fixed.
My old accord used approx 1 qrt every 3000 miles which i felt was acceptable considering it had well over 100K miles on it and was driven, how should we say, VERY hard.
Kestas
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H2GURU, modern engines are made with less tension on the piston rings for less friction and better fuel economy. That may be why engines seem looser. The trade-off is higher oil consumption. With looser rings, I'm surprised I don't see more oil consumption on modern engines than I do now.
I remember seeing published data that allows up to one quart every 500 miles before action needs to be taken to fix the engine.
I remember seeing published data that allows up to one quart every 500 miles before action needs to be taken to fix the engine.
No problem. For all I know your Toyota may be made in the U.S.A. My last F150 was made in Canada.
Incidentally, GM specs something like one quart every 2K as maximum acceptable oil consumption. It's in a TSB somewhere that I don't have access to on this computer, so I can't check to be sure what the exact amount is. But it's definitely not as much as 1 quart every 1K.
Wonder how we'd react if Microsoft told us it was normal for Windows to crash 3x a day...oh wait, never mind.
I've read for years the "1qt/1,000miles" rule as being normal.
Down here, no one would put up with that consumption. 1qt/3,000miles would occur at 160-250,000km, and the car would go in for a head job.
GM found that with the low tension rings in the V-6. Engine damage could occur within the normal OCI (6k miles), with the sump emptying.
They didn't fix the consumption, but first overfilled the sump, then enlarged and overfilled so it wouldn't empty between services.
Stating that such consumption is normal is simply taking the buyer for a ride.
If they built them to not consume, then phos limits (tailored to the worst of the factory oil burners) wouldn't be anything like they are currently.
Down here, no one would put up with that consumption. 1qt/3,000miles would occur at 160-250,000km, and the car would go in for a head job.
GM found that with the low tension rings in the V-6. Engine damage could occur within the normal OCI (6k miles), with the sump emptying.
They didn't fix the consumption, but first overfilled the sump, then enlarged and overfilled so it wouldn't empty between services.
Stating that such consumption is normal is simply taking the buyer for a ride.
If they built them to not consume, then phos limits (tailored to the worst of the factory oil burners) wouldn't be anything like they are currently.
It's not only the better fit and finish, but the fact that the engines are run through their paces at the factory now, which is huge for break in.
If a new engine burns 1 qt. in 1000 miles, I would be very surprised. That would be unusual.
I think the mfrs. are allaying the fears of people who experience ANY oil usage.
If a new engine burns 1 qt. in 1000 miles, I would be very surprised. That would be unusual.
I think the mfrs. are allaying the fears of people who experience ANY oil usage.
In the engine section of the Ford factory shop manuals is a detailed description of the oil consumption tests we are to carry out before asking for warranty relief re excessive oil consumption. As recently as four years ago the allowable consumption rate per Ford was 900 miles per quart. HA! That figure was okay with exactly ZERO customers I encountered! The manuals for newer cars read exactly the same until you get to the mileage figure and now show 1500 miles as acceptable consumption. The reaction from customers is about the same, as you might imagine. These are mostly Lincoln owners, most of whom have never owned a car that needed much more than a quart between changes, if that.
I just know my 95 BMW with 135,000 miles does not seem to use any oil at all between oil/filter changes every 4-6,000 miles. BTW, Does a 95 model car engine count as "modern machining"?
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