Why does modern car use lot of engine oil?
Discussion
why do they consume the engine oil like 1 litre every 1000 miles?
Is this because to mask the manufacturer's mpg rating? the engine burn oil to reduce the fuel consumption to give false reading on mpg ?
lot of Car I owned which is made from 90's don't burn oil much as this modern cars.
Is this because to mask the manufacturer's mpg rating? the engine burn oil to reduce the fuel consumption to give false reading on mpg ?
lot of Car I owned which is made from 90's don't burn oil much as this modern cars.
currybum said:
vrooom said:
why do they consume the engine oil like 1 litre every 1000 miles?
Is this because to mask the manufacturer's mpg rating? the engine burn oil to reduce the fuel consumption to give false reading on mpg ?
lot of Car I owned which is made from 90's don't burn oil much as this modern cars.
There is no reason why they need to, it's just a lot of hard work and money to do the job properly.... VAG seem to have decided not to bother.Is this because to mask the manufacturer's mpg rating? the engine burn oil to reduce the fuel consumption to give false reading on mpg ?
lot of Car I owned which is made from 90's don't burn oil much as this modern cars.
vrooom said:
why do they consume the engine oil like 1 litre every 1000 miles?
Is this because to mask the manufacturer's mpg rating? the engine burn oil to reduce the fuel consumption to give false reading on mpg ?
lot of Car I owned which is made from 90's don't burn oil much as this modern cars.
Generally speaking, they don't.Is this because to mask the manufacturer's mpg rating? the engine burn oil to reduce the fuel consumption to give false reading on mpg ?
lot of Car I owned which is made from 90's don't burn oil much as this modern cars.
What has happened is that the quest for increased efficiency, and hence low fuel consumption has resulted in the engine designers and developers trying every possible trick to reduce the friction that occurs between moving parts in an engine. And the largest single friction creation occurs between the piston and the cylinder bores. In the old days, the primary concern was to seal the cylinder, keeping the combustion products above the piston, and the lubrication oil below it. To do this, engines has thick iron blocks, and multiple "high tension" piston rings to scrape the lubricating oil off the bore on the down stroke. But, those multiple rings, pressing hard against the bore created a lot of friction. Modern engines have moved to alluminium blocks (for mass reduction) and use clever modern "hard" coatings on that material to produce a suitable surface for the much smaller, and lower tension rings to run up and down on. Overall, this solution has reduced sliding friction by around 30%.
Most of the time, this solution works very well, but what can happen is that when a car has not been driven hard, or is driven in a certain fashion (lots of short, cold journeys) the sealing capability of that system is reduced, resulting in a high oil consumption.
In reality, this is an isolated effect, with the vast vast majority of modern cars not needing even a top up of oil between much much longer service intervals. In certain cases, design or manufacturing defects have lead to certain cars getting a "reputation" for high oil consumption, but even then, it only effects a small percentage of those cars in the fleet.
Edited by anonymous-user on Thursday 22 May 22:12
Max_Torque said:
Most of the time, this solution works very well, but what can happen is that when a car has not been driven hard, or is driven in a certain fashion (lots of short, cold journeys) the sealing capability of that system is reduced, resulting in a high oil consumption.
Interesting, that probably explains whey my old 2.8 passat drank 1 litre per 1000 miles when I first got it but only ever got improved over time to the point were I hardly ever needed to top it up.Max_Torque said:
currybum said:
There is no reason why they need to, it's just a lot of hard work and money to do the job properly.... VAG seem to have decided not to bother.
That^^^^ sort of thing belongs in the "car myths thread"......The 2.0 TFSI and the 4.2 V8 being particularly bad offenders.
What surprises me is how engines differ so much I have only done 6k miles in my E90 330i 2006 model which has 54k miles on it now and put 2 litres of oil in it already and its half way to needing another litre yet we have done nearly 54k miles in the 2012 Audi TTS and I have only put 2 litres in that in total...it just doesn't make sense to me.
currybum said:
Best of all its almost impossible it model in CAE, so if you want to do the job properly while maintaining the friction benefits you have to spend the money, take the time and do the engineering.
And charge your customers accordingly, or...currybum said:
Either that of you don't bother and tell everyone that high consumption is normal.
... charge your customers less and sell more cars. Guess which argument wins at boardroom level.BrownBottle said:
Max_Torque said:
currybum said:
There is no reason why they need to, it's just a lot of hard work and money to do the job properly.... VAG seem to have decided not to bother.
That^^^^ sort of thing belongs in the "car myths thread"......The 2.0 TFSI and the 4.2 V8 being particularly bad offenders.
That said, the 1.9 PD engine in my Octavia used to get through almost 2 litres between services, the 1.6 CR I have now hasn't used a drop over the last 40k.
But none of my previous cars consumed oil to the extent to PD engine did, if at all, and they were all <1k bangers.
I think this 'not doing it properly' sentiment is rubbish. Is the implication that this is a materials and tolerances issue? Because I highly doubt it is.
Oil consumption has a lot to do with the way the engine is used and even more to do with the way it is broken in. These is a school of thought in Motorsport circles that if you want an engine to break in properly, ensuring optimal cylinder compression, it should be used moderately hard during the break-in process. If an engine idles a lot during break-in, or gets driven very gently, the engine may never break in as well as one which has been used properly. I'd be interested to hear from any resident engine experts if this theory has any merit.
Oil consumption has a lot to do with the way the engine is used and even more to do with the way it is broken in. These is a school of thought in Motorsport circles that if you want an engine to break in properly, ensuring optimal cylinder compression, it should be used moderately hard during the break-in process. If an engine idles a lot during break-in, or gets driven very gently, the engine may never break in as well as one which has been used properly. I'd be interested to hear from any resident engine experts if this theory has any merit.
My experience of engine break ins on the dyno is that varying speed and load as much as possible gets the most consistent results afterwards between engines. Apart from any severe differences in the build for whatever reason.
Actually, I'm not sure there is a "right" way to run an engine in. So long as it isn't sat at a single speed / load condition for long periods of time then a group of engines all run in the same way seem to behave largely the same. I guess a lot of that is due to loading the rings so that they wear evenly under all conditions and thus provide optimal sealing regardless of tan load.
Actually, I'm not sure there is a "right" way to run an engine in. So long as it isn't sat at a single speed / load condition for long periods of time then a group of engines all run in the same way seem to behave largely the same. I guess a lot of that is due to loading the rings so that they wear evenly under all conditions and thus provide optimal sealing regardless of tan load.
Better manufacturing methods and machines have seen a steady reduction in limits and fits of components, as a design engineer in a technically complex field we can hold a 0.03mm tolerance band and churn out components very quickly. So I would say that excess oil consumption has nothing to do with shoddy design or modern manufacturing methods.
I would suggest that you have been unlucky, over the last 6 years I have had new cars from Audi, BMW and now Mercedes none have needed more than a litre of oil between services. The BMW, first service was at 26,000 miles at 18 months and the Mercedes has not needed any and that's a 3.0l diesel.
The last used car I purchased in 2007 was an ex demonstrator Z4, that had been bought by a policeman in London, it used a litre of fuel every few thousand miles. Ex demonstrators, cars that are enjoyed whilst cold and/or used for short journeys will use more oil, why? Because engines are designed and toleranced hot, that is when cold they are tighter than when warm due to thermal expansion. If the engine is worked hard when cold wear increases.....simple.
I would suggest that you have been unlucky, over the last 6 years I have had new cars from Audi, BMW and now Mercedes none have needed more than a litre of oil between services. The BMW, first service was at 26,000 miles at 18 months and the Mercedes has not needed any and that's a 3.0l diesel.
The last used car I purchased in 2007 was an ex demonstrator Z4, that had been bought by a policeman in London, it used a litre of fuel every few thousand miles. Ex demonstrators, cars that are enjoyed whilst cold and/or used for short journeys will use more oil, why? Because engines are designed and toleranced hot, that is when cold they are tighter than when warm due to thermal expansion. If the engine is worked hard when cold wear increases.....simple.
One of my Hondas began using more and more oil, to a point that the dipstick was nearly dry after 2 tanks of fuel - about 700 miles. Ultimately I knew it was rings so took the engine to bits. The oil rings had worn heavily on 1 cylinder compared to the others, so much that the plug had oil deposits built up on it. Bores were glazed though only cylinder no3 was to fault.
Honed, new rings and so far coming up to the 3rd tank without using any oil. It was rather extreme in that at idle you would rev I was rather surprised that it needed doing, the sort of thing that you'd expect at 150k, not 78. Good job I check the oil and not rely on Hondas reliability record....
VTEC claims to use a bit of oil, though the 1 ltr per 1000 miles IMO is indicating an issue elsewhere as the 2.4 Accord I had before it used no oil, my Transit hasnt had a top up since I changed the oil 11 months ago in 7k miles.
I'd say it highlights the short journeys cars are used for now, rather than an attempt at manufacturers to fiddle economy figures.
When I was a tech at Mazda we had a few cars that came in with almost no oil and bald tyres at their first (9000) service. Under the 1ltr per thousand miles but still not clever if the owner doesnt check.
Honed, new rings and so far coming up to the 3rd tank without using any oil. It was rather extreme in that at idle you would rev I was rather surprised that it needed doing, the sort of thing that you'd expect at 150k, not 78. Good job I check the oil and not rely on Hondas reliability record....
VTEC claims to use a bit of oil, though the 1 ltr per 1000 miles IMO is indicating an issue elsewhere as the 2.4 Accord I had before it used no oil, my Transit hasnt had a top up since I changed the oil 11 months ago in 7k miles.
I'd say it highlights the short journeys cars are used for now, rather than an attempt at manufacturers to fiddle economy figures.
When I was a tech at Mazda we had a few cars that came in with almost no oil and bald tyres at their first (9000) service. Under the 1ltr per thousand miles but still not clever if the owner doesnt check.
With these feet said:
I'd say it highlights the short journeys cars are used for now, rather than an attempt at manufacturers to fiddle economy figures.
Can't argue with that, so many of my neighbours will drive the <1km to the local shop to get milk, or a paper, or anything else they need. I certainly noticed that with my old Octavia vRS with the 1.8T that long journeys would see 10k with barely noticeable consumption while the same duration of shorter trips would see me needing about a litre over that distance. They weren't true short journeys though, but still they weren't motorway cruising for an 800 mile round trip either.In my case both cars were delivered with <10 miles on the clock, both were run in the same way, and both driven the same way on the same roads by myself only. (60 mile each way commute).
There must bé something in the pd design that makes it use oil, as opposed to the CR engine.
There were several on the fleet, all used oil.
At least my fuel card covered it, as the stuff was more expensive than gin!
There must bé something in the pd design that makes it use oil, as opposed to the CR engine.
There were several on the fleet, all used oil.
At least my fuel card covered it, as the stuff was more expensive than gin!
cerb4.5lee said:
What surprises me is how engines differ so much I have only done 6k miles in my E90 330i 2006 model which has 54k miles on it now and put 2 litres of oil in it already and its half way to needing another litre yet we have done nearly 54k miles in the 2012 Audi TTS and I have only put 2 litres in that in total...it just doesn't make sense to me.
Anecdotally seems to be a big jump in oil consumption from m52tu to m54. m52tu seems more or less an m54 head on an m52 block so the comments about ring packs make sense. My m52tub28 is on 216k miles and the level barely moves. I don't think many of the higher consumption engines will make it to these milages just because the chance is higher that they will end up being run with no oil in them at some point.BritishRacinGrin said:
I think this 'not doing it properly' sentiment is rubbish. Is the implication that this is a materials and tolerances issue? Because I highly doubt it is.
Oil consumption has a lot to do with the way the engine is used and even more to do with the way it is broken in. These is a school of thought in Motorsport circles that if you want an engine to break in properly, ensuring optimal cylinder compression, it should be used moderately hard during the break-in process. If an engine idles a lot during break-in, or gets driven very gently, the engine may never break in as well as one which has been used properly. I'd be interested to hear from any resident engine experts if this theory has any merit.
Oil consumption has a lot to do with the way the engine is used and even more to do with the way it is broken in. These is a school of thought in Motorsport circles that if you want an engine to break in properly, ensuring optimal cylinder compression, it should be used moderately hard during the break-in process. If an engine idles a lot during break-in, or gets driven very gently, the engine may never break in as well as one which has been used properly. I'd be interested to hear from any resident engine experts if this theory has any merit.
http://www.mototuneusa.com/break_in_secrets.htm
I've used this method on bike engine's.
2003 Golf TDI with 137k and 2012 320d with 42k.
The 320d dipstick reading has never moved off the MAX marker from new. First service at 19k, second at 38k, but never topped up in between.
The Golf uses about half a litre in 6,000 miles.
The last car I had with a serious oil consumption issue was a 1997 Polo diesel. A litre per 1,000 miles.
The 320d dipstick reading has never moved off the MAX marker from new. First service at 19k, second at 38k, but never topped up in between.
The Golf uses about half a litre in 6,000 miles.
The last car I had with a serious oil consumption issue was a 1997 Polo diesel. A litre per 1,000 miles.
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