Oil change interval

pvr · Post by **pvr** » Sat Mar 02, 2024 2:07 pm

Was reading an article about engine oil where the conclusion was that oil doesn’t deteriorate by time and only by miles.

Thought that was interesting as I always thought that the annual change of oil on the Golf that might do 300 miles or so, could be excessive so might as well skip every other year.

Will see if I can locate the article

Mr Tidy · Post by **Mr Tidy** » Sat Mar 02, 2024 8:09 pm

I'd like to see that article.

When I was still doing business mileage my BMWs always needed an oil change based on mileage, but now I've stopped working they get done on time so every 2 years which seems to be around 6/7 thousand miles. Any more frequent than that just struck me as overkill so it would be good to see if I may be right!

Nanu · Post by **Nanu** » Sat Mar 02, 2024 9:37 pm

Surely if oil deteriorated over time, each can of oil would have a sell by date. Also if you purchased it towards the end of that date, would that mean an even earlier oil service once you put an oil that's already say 6 months old into your car?

Car booked in for its second service which includes an oil service and plugs, on Thursday with 18K on the clock so will ask.

pvr · Post by **pvr** » Sat Mar 02, 2024 10:38 pm

Haven’t found it yet, will check my desktop machine history Monday.

It was showing that an analysis of a 14 year old open oil bottle that nothing had deteriorated.

Mr Tidy · Post by **Mr Tidy** » Sat Mar 02, 2024 10:44 pm

I can see why old fashioned mineral oils might deteriorate over time, but modern oils are synthetic based so I'd hope they wouldn't.

Pondrew · Post by **Pondrew** » Sat Mar 02, 2024 10:49 pm

pvr wrote: ↑Sat Mar 02, 2024 10:38 pm It was showing that an analysis of a 14 year old open oil bottle that nothing had deteriorated.

A bit different to it sitting in a sealed metal 'box' though.

Pondrew · Post by **Pondrew** » Sat Mar 02, 2024 10:50 pm

Mr Tidy wrote: ↑Sat Mar 02, 2024 10:44 pm I can see why old fashioned mineral oils might deteriorate over time

It took millions of years to form, so don't see why TBH.

TitanTim · Post by **TitanTim** » Sun Mar 03, 2024 12:00 am

Always had the BMWs serviced every two years regardless.

Don't BMW say their gearboxes are sealed for life but if you've seen the state of the oil at 60k miles it's not a pretty sight.

Tim.

buzyg · Post by **buzyg** » Sun Mar 03, 2024 1:22 am

Interesting thread. Hope you can find the article to share.

raymond.harper · Post by **raymond.harper** » Sun Mar 03, 2024 9:02 am

I think it was this article https://www.reddit.com/r/cars/comments/ ... rval_myth/ https://podcasts.apple.com/us/podcast/1 ... 0637442335

pvr · Post by **pvr** » Sun Mar 03, 2024 9:20 am

Yep, thanks Ray - that was the one

enuff_zed · Post by **enuff_zed** » Sun Mar 03, 2024 9:36 am

But if it goes into your car and does a bit of work it then sits in the sump and oil ways potentially holding foreign matter and moisture in it.
Not quite the same as leaving the top off a bottle.

pvr · Post by **pvr** » Sun Mar 03, 2024 9:46 am

But isn’t that the case with the 993 example where it hadn’t deteriorated ?

enuff_zed · Post by **enuff_zed** » Sun Mar 03, 2024 10:02 am

pvr wrote: ↑Sun Mar 03, 2024 9:46 am But isn’t that the case with the 993 example where it hadn’t deteriorated ?

Yup.
But I was meaning that the oil may stay the same but what is it holding within it?

pvr · Post by **pvr** » Sun Mar 03, 2024 10:08 am

Which comes back to how many miles it has done with the oil, the more miles the more pollution

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