Oil Consumption...The ailment of the modern car
Discussion
My last two cars, a modernish BMW and Audi both liked to drink a bit of the black stuff and a straw poll at work seems to indicate that this is a worryingly common trend.
Now call me old fashioned but I was always brought up to believe that if a car used oil, it was almost always not a good sign. In fact it was usually a good indicator of something being borked in the err oily bits.
However having asked various main dealer technicians about this over the years, I've always gotten the response "they all do that sir". One went a bit further and actually explained to me that in an effort to reduce emissions, modern cars, especially turbocharged cars ran a lot hotter which is why a certain amount of oil use was expected.
So I put it to the PH experts, is this feasible or are they just telling me this to make me go away? Is the modern engine just more susceptible due to most of them being turbocharged, DFI etc. Is it normal\healthy for a car to use a bit of oil, or like me do you think it's a whole new thing to think that oil usage has become acceptable?
Now call me old fashioned but I was always brought up to believe that if a car used oil, it was almost always not a good sign. In fact it was usually a good indicator of something being borked in the err oily bits.
However having asked various main dealer technicians about this over the years, I've always gotten the response "they all do that sir". One went a bit further and actually explained to me that in an effort to reduce emissions, modern cars, especially turbocharged cars ran a lot hotter which is why a certain amount of oil use was expected.
So I put it to the PH experts, is this feasible or are they just telling me this to make me go away? Is the modern engine just more susceptible due to most of them being turbocharged, DFI etc. Is it normal\healthy for a car to use a bit of oil, or like me do you think it's a whole new thing to think that oil usage has become acceptable?
They probably do run a bit hotter than they used to for efficiency, and they also often run thinner oil for the same reason. Both might increase oil consumption.
Possibly most significantly, to reduce internal friction the piston rings have to push on the bores as lightly as they can get away with. If people were happy with the efficiency drop, they could make the oil scraper rings push harder and less oil would be burnt. I'm not sure if the materials used mean they have to be more careful with rings too-an old cast iron block probably didn't have to worry as much about piston rings causing bore wear.
Possibly most significantly, to reduce internal friction the piston rings have to push on the bores as lightly as they can get away with. If people were happy with the efficiency drop, they could make the oil scraper rings push harder and less oil would be burnt. I'm not sure if the materials used mean they have to be more careful with rings too-an old cast iron block probably didn't have to worry as much about piston rings causing bore wear.
Yep it definitely seems to effect some cars more than others but seems to be more prevalent on modern turbocharged petrol engines. Now some might argue that the hot turbo might be a factor but I owned two high performance Japanese turbo cars in the 90's and early 00's and neither used a drop of oil so there must be something else at play. Could emissions really be to blame?
I just can't seem to get my head around a car which uses oil as I can't help but associate it with 30 year old classics or poorly maintained sheds.
I just can't seem to get my head around a car which uses oil as I can't help but associate it with 30 year old classics or poorly maintained sheds.
In my experiance its down to luck.
I owned a Clio 197 at the same time as a friend, his drunk oil (a litre every 2,000) mine used none at all.
I always thought it was to do with tolerances inside the engine, and the tolerances can vary in manufacture (piston rings may not seal as well in the bores from one engine to the next)
I owned a Clio 197 at the same time as a friend, his drunk oil (a litre every 2,000) mine used none at all.
I always thought it was to do with tolerances inside the engine, and the tolerances can vary in manufacture (piston rings may not seal as well in the bores from one engine to the next)
sonarbell said:
Erm seems like BMW is the common denominator at the moment in this ? Just saying like ....
And? The majority of cars that use oil do so well within acceptable tolerances. I don't see it as an issue. A litre of oil is £12 or so for the good stuff, and I have to top up every 6-8 weeks. £12 is about 60 miles of fuel at a guess.Edited by sparks_E39 on Thursday 26th June 01:11
Ok. Just some wibble from an old head at a very early hour...
Forget the BMW schnizzle.....
Petrol = High Vacuum on overrun because of butterfly valve in manifold.
Diesel = No Butterfly valve.
Short journeys = Insufficient heat in engine causing poor tolerences in valve stem clearance.
High vacuum and insufficient heat means high oil consumption..
So just using the above info then petrols are likely to use more oil than diesels.
I know its not the complete and definitive guide to engines but its a small part of oil high oil consumption...
Just saying like........
Forget the BMW schnizzle.....
Petrol = High Vacuum on overrun because of butterfly valve in manifold.
Diesel = No Butterfly valve.
Short journeys = Insufficient heat in engine causing poor tolerences in valve stem clearance.
High vacuum and insufficient heat means high oil consumption..
So just using the above info then petrols are likely to use more oil than diesels.
I know its not the complete and definitive guide to engines but its a small part of oil high oil consumption...
Just saying like........
sparks_E39 said:
My 530i uses a litre every 1500ish miles. It's within known tolerances, isn't expensive to keep on top of and there isn't anything terribly wrong with it, so it's a non issue.
^ This. All my cars burn a little oil. The cost is insignificant.It's down to the engineering need to reduce friction to achieve power and fuel consumption expectations of the market. Everyone knows that the book MPG claims can't be achieved in real life however if a manufacturer said "Yeah but no but our MPG is much less but our engines don't use any oil" everyone would still select their hatchback based on the MPG figure then complain about oil consumption later.
I don't even think the cost of the oil is what grates on the British in particular, but it's the effrontry of actually having to do these old-fashioned checks once a month like your grandfather and father told you to. You know, like check there is any oil on the dipstick, know the difference between the coolant and PAS reservoirs, have a gander at the tyres and confirm that they're still round and have that tready stuff still on them. Anything that demands more attention that filling it with fuel equates to "broken" to the modern British person with their supremely busy "lifestyle" of watching other people play sports on TV.
I don't mind the expense as it's only 15 quid every few months and my electronic computer tells me everything so I don't even need to get my hands dirty or disrupt my busy lifestyle 
I was more interested in why it happens, why manufacturers seem to deem it acceptable and more importantly why they don't make more of a point of telling you, it's almost as if they are ashamed of it.
I was more interested in why it happens, why manufacturers seem to deem it acceptable and more importantly why they don't make more of a point of telling you, it's almost as if they are ashamed of it.
Our R56 Mini Cooper S with 35000 miles uses about a litre per 500 miles. With a 1.6l engine. I took it to the dealership and told them that there must be something very wrong with the engine but they said that that is still "within tolerances". Right... if I wanted a car that burns oil instead of petrol I would have just bought a diesel. 
To add insult to injury the dipstick is almost impossible to read.
To add insult to injury the dipstick is almost impossible to read.
I had a 2.0 tsfi A4 and it used a litre every 1500 miles. It had to go, as in over 30 years of driving I've never had to top up the oil in any car even some old sheds.
Being an engineer and a bit OCD Once I knew it was using so much it just annoyed me too much, I even traded it in to a dealer which I have never done .because I didn't want to pass it on to some one.
Being an engineer and a bit OCD Once I knew it was using so much it just annoyed me too much, I even traded it in to a dealer which I have never done .because I didn't want to pass it on to some one.
A cynic might suggest the engines are designed to burn oil so the typical driver, who never opens the bonnet, will trash the engine and generate expensive business for the dealer network? Or maybe not, as this would happen within the warranty period...
None of my cars have burned oil, though my current steed is 2004 vintage and diesel so I've not tried a newer petrol car.
None of my cars have burned oil, though my current steed is 2004 vintage and diesel so I've not tried a newer petrol car.
Easternlight said:
I had a 2.0 tsfi A4 and it used a litre every 1500 miles. It had to go, as in over 30 years of driving I've never had to top up the oil in any car even some old sheds.
Being an engineer and a bit OCD Once I knew it was using so much it just annoyed me too much, I even traded it in to a dealer which I have never done .because I didn't want to pass it on to some one.
It's well known for the TFSI engines to use oil, part of how the engines work and WELL within the guidelines.Being an engineer and a bit OCD Once I knew it was using so much it just annoyed me too much, I even traded it in to a dealer which I have never done .because I didn't want to pass it on to some one.
1 litre in 1500 is not a lot, if you sold the car for that reason then who's lost out really.
My TFSI I've had to top up about 400ML in my ownership between services (18k).
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