Oil consumption

[Magnet]

Thanks Stason, but I think you are contradicting yourself to some degree:- 

You add 1ltr every 2/3K miles.

You say it isn’t normal to add 1 ltr at 1K to the same 2k miles. 
Kind regards,

Gareth.

[Optimus]

My experience working for main dealer and dealing with this issue/concern was that from a technical aspect adding oil for new cars under 6k miles every 2k miles was normal. After 6k miles it seemed to be less of an issue until vehicles got to 80k plus (wear and tear)

what I was summarising was that you have a situation where it seemed to be normal expected then it was unusual then expected depending on use age and wear and tear.

new vehicles though bedded in at factory to a degree always use more oil then after say 20k miles. 
 

the additional point I was making was that the oil in these vehicles is very very thin high viscosity and easily evaporates so factoring this in with usage those who do motorway miles (sustained temperatures) experience higher degradation of oil and suffer the most with oil loss.

it is normal to expect to be putting oil in every so often but not if is less as quoted above.

the difference between petrol and diesel oil consumption is significant.

 

diesel’s will use more oil then petrol as i understand oil is difference grade and running (internal combustion) temperatures are different.  
therefor using petrol engines by comparison should be disregarded.

The oil consumption is concerning but it is from my experience normal across the board. 
 

where it’s more concerning is the difference between extended use and short term use because it seems this is where most people are complaining where there is instances of 3000 mile or less topping up 1 litre of oil as a result of the warning indicator. 
 

 

Edited September 25 by Optimus

[Magnet]

Thanks Stason,

To try to boil this down:- 

It’s not uncommon for engines to use some oil over the first few thousand miles until they bed in, but is uncommon after that mileage has been covered.

So OP Brian’s car at 30K Kms. should not be using the amount of oil it does -?

’Engine oil evaporates…’. Sorry for the contra opinion, but I think oil technologists would be disappointed to hear that! 
Kind regards,

Gareth. 

[cliffcoggin]

Whether the oil is evaporating or burning or leaking is all a bit academic until Brian tells us what his real consumption is. Until that happens I shall add nothing more to the discussion.

Well Brian, are you going to answer the question?

[Optimus]

23 hours ago, Magnet said:

Thanks Stason,

To try to boil this down:- 

It’s not uncommon for engines to use some oil over the first few thousand miles until they bed in, but is uncommon after that mileage has been covered.

So OP Brian’s car at 30K Kms. should not be using the amount of oil it does -?

’Engine oil evaporates…’. Sorry for the contra opinion, but I think oil technologists would be disappointed to hear that! 
Kind regards,

Gareth. 

https://penriteoil.com.au/knowledge-centre/Miscellaneous/242/what-causes-oil-burning-and-oil-consumption/400#:~:text=Oil burns when at its,valve stems%2C seals and guides.
 

very useful thread about oil usage and degradation. But yes all oil including synthetic evaporates! 

[Brian McG]

The level is now approximately 3/4 between the max and min on the monitor.  I'll check again after a few thousand km.

[Magnet]

Thanks Stason,

Penrite - long established supplier of classic car oils. Don’t think their market is aimed at modern vehicles. 
Am I missing the bit about oil evaporation - especially in closed systems-? 
Kind regards,

Gareth.

[Optimus]

Even in closed systems low tension oil evaporation takes place when it becomes a gaseous state and be deposited else around the vacuum pipes/inlet manifold etc. evaporation is a thing even in closed systems I won’t go into too much detail but F1 engines burn through oil like crazy something like 3-5litres per race setup. The reason why I draw this comparison is that they specifically use low tension oil types similar to modern emission friendly cars to create less drag on movement parts and increase efficiency. 
 

whilst I understand the f1 engines are operating constantly at high rpm and temperature. If you are doing motorway mileages frequently you could be burning off a litre of oil every few thousand miles.

i have added 5litres of oil since 0 miles. My TDi 40 A6 has done 17568 miles (28273km) and is 14 months old. Roughly about 40% of my driving time is sat at 60mph+. Journey times averaging 56mins.

 

 

 

Edited September 27 by Optimus

[Jobbo]

I'm aware that it's been a while since this thread was updated but thought I'd add my experience.  I got my S6 TDI new in April 2023 and have now done 36,000 miles in it, and it's had two services (at about 15k and about 30k miles).  Before the first service I had to top up with a litre of oil - as per a message on the MMI.  I'd noticed that the oil level was gradually going down because I'd checked it every once in a while, so it wasn't a surprise.  After the first service it came back with the oil level mid-way according to the MMI.  I had the garage pick it up and top it up to full because if it used 1l in less than 15k miles, I didn't want to have to top it up again maybe 7-8k miles after service.  From full on the MMI it dropped but didn't need topping up again before the 30k service.  And since then it doesn't appear to have gone down (they did deliver it back with the oil level mid-way on the MMI again, but I didn't make a fuss this time).

So I'd guess my car was still bedding in until maybe past 20k miles (32k km); perhaps longer than you'd expect.