Oil & Filter Change

[Andy 4D]

I’m about to do an oil & filter change on my Z3. She’s a 2.0l 6 and currently has close to 140000 miles. I’ll be using Gulf Formula GX 5w-40 fully synthetic with a Mahle oil filter. I know you would normally change every 12 months or so but as I probably only cover 2-3K a year with her, is this really necessary. I know the oil will degrade over time and the viscosity may change but after a year or 2 how bad could it get, could I stretch the oil change to 24 months for example. I don’t mind doing it, I was really just wondering what other members thought or did with their cars.
Sorry if this subject has been covered somewhere else on the forum, I did search but couldn’t see anything.

 

[Ianmc]

All my cars (each do around 7K miles per year) have an oil and filter change every 12 months. Maybe not essential but good, relatively cheap, preventative maintenance; likely just as important for low mileage use.

 

[black fingernail]

I change the oil and filter in all my vehicles every 12 months regardless of mileage.

 

[B21]

The long life oils are designed as their name implies for extended time and mileage..you can’t say definitively it will be harmful…a compromise maybe is to just change the oil annually and the nice Mahle filter every other year..

 

[colb]

5W40 is a good choice for a high mileage car, personally mine only has low mileage put on her but aim to change oil and filter at least every 12 months maybe stretching it to 18 months. Always use a good brand filter that supplies the small O rings that fit on the cap stem that prevent drain back from the filter when engine is off.

 

[Andy 4D]

The long life oils are designed as their name implies for extended time and mileage..you can’t say definitively it will be harmful…a compromise maybe is to just change the oil annually and the nice Mahle filter every other year..
[/QUOTE
I appreciate all the feedback and I’m guessing the general consensus is “Change the oil every 12 months” and don’t be such a tight fisted git Andy!!!!

I was just pondering the idea of how time/mileage affects the oils condition. For example, if I were to do an oil change then only drive 100 miles over the next 12 months would the engine then require another oil change?
……Somebody tell me to shut up please!!!!!

 

[B21]

Time itself is not a killer.. ad hoc, short duration, infrequent use is the worse...I gather train diesel engines can go 250k miles before an oil change....you'd be best to do that 100 miles in one trip at between 1/4 and 1/2 throttle and 3k-5k..

If you are doing a 100 miles PA and it not 100 start-ups then maybe 2 years is OK..

General view for maximum longevity is 3-5k miles per oil change..or anually..whichever comes first..far cry from BMW's 30k km and 2 years..

 

[Andy 4D]

Time itself is not a killer.. ad hoc, short duration, infrequent use is the worse...I gather train diesel engines can go 250k miles before an oil change....you'd be best to do that 100 miles in one trip at between 1/4 and 1/2 throttle and 3k-5k..

If you are doing a 100 miles PA and it not 100 start-ups then maybe 2 years is OK..

General view for maximum longevity is 3-5k miles per oil change..or anually..whichever comes first..far cry from BMW's 30k km and 2 years..

That’s a very thorough answer, thank you and I especially like the reference to diesel trains. I think I’ll just change the oil every 12 months and stop asking stupid questions from now on. Thanks again.

 

[Pond]

From what I have gleaned about engine oil, especially synthetic, if it is sitting idle then there will be no degradation (or not realistically) for a few years.
It is very short journeys that play havoc with oil, due to water vapour constantly evaporating and condensing but never being removed.

Oil filters, if left unused for a relatively short period, are more important to change as the moisture in the oil will evaporate and can 'gum' which reduces the filtering ability.

Not scientific fact, admittedly!

 

[t-tony]

For what an oil filter costs its not worth leaving it, plus you get a better drain of the system when you remove the filter.

Tony.